VEBM090100_WF550-3_T-3

6KRS0DQXDO

VEBM090100

75$6+&203$.725 SERIAL NUMBER WF550-3 WF550T-3

W089-50001 AND UP W090-50001 AND UP

•

This shop manual may contain attachments and optional equipment that are not available in your area. Please consult your local KOMATSU distributor for those items you may require. Materials and specifications are subject to change without notice.

•

WF550-3, WF550T-3 mount the S6D140-2 engine. For details of the engine, see the 6D140-2 Series Engine Shop Manual

© 2001 All Rights Reserved Printed in Europe 07/01

10-2

WF550-3 / WF550T-3

CONTENTS No. of page

00

SAFETY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 00-1

01

GENERAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 01-1

10

STRUCTURE AND FUNCTION . . . . . . . . . . . . . . . . . . . . . 10-1

20

TESTING AND ADJUSTING . . . . . . . . . . . . . . . . . . . . . . . 20-1

30

DISASSEMBLY AND ASSEMBLY . . . . . . . . . . . . . . . . . . 30-1

40

MAINTENANCE STANDARD . . . . . . . . . . . . . . . . . . . . . . 40-1

90

OTHERS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90-1

WF550-3 / WF550T-3

10-3

10-4

WF550-3 / WF550T-3

00 SAFETY Safety notice . . . . . . . . . . . . . . . . . . . . . . . . . . 00-2 Foreword . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 00-6 How to read the shop manual . . . . . . . . . . . . Volumes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Distribution and updating . . . . . . . . . . . . . . . . . Filing method . . . . . . . . . . . . . . . . . . . . . . . . . . Symbols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

00-7 00-7 00-7 00-7 00-8

Hoisting instructions . . . . . . . . . . . . . . . . . . . 00-9

WF550-3 / WF550T-3

00-1

Safety notice

SAFETY

Safety notice

Important Safety Notice Proper service and repair is extremely important for safe machine operation. Some of the described service and repair techniques require the use of tools specially designed by Komatsu for the specific purpose. To prevent injury to workers, the symbol is used to mark safety precautions in this manual. The cautions accompanying these symbols must always be followed carefully. If any dangerous situation arises or may possibly arise, first consider safety, and take the necessary actions to deal with the situation.

General Precautions Mistakes in operation are extremely dangerous. Read the OPERATION AND MAINTENANCE MANUAL carefully before operating the machine! Always follow the safety rules valid in your country carefully!

1. Before carrying out any greasing or repairs, read all the precautions given on the decals which are fixed to the machine. 2. When carrying out any operation, always wear safety shoes and helmet. Do not wear loose work clothes, or clothes with buttons missing. •

Always wear safety glasses when hitting parts with a hammer.

•

Always wear safety glasses when grinding parts with a grinder, etc.

3. If welding repairs are needed, always have a trained, experienced welder carry out the work. When carrying out welding work, always wear welding gloves, apron, glasses, cap and other clothes suited for welding work. 4. When carrying out any operation with two or more workers, always agree on the operating procedure before starting. Always inform your fellow workers before starting any step of the operation. Before starting work, hang UNDER REPAIR signs on the controls in the operator's compartment. 5. Keep all tools in good condition and learn the correct way to use them. 6. Decide a place in the repair workshop to keep tools and removed parts. Always keep the tools and parts in their correct places. Always keep the work area clean and make sure that there is no dirt or oil on the floor. Never smoke while working. Smoke only in the areas provided for smoking.

00-2

WF550-3 / WF550T-3

SAFETY

Safety notice

Preparations for work 1. Before adding oil or making any repairs, park the machine on hard, level ground, and block the wheels or tracks to prevent the machine from moving. 2. Before starting work, lower blade, ripper, bucket or any other work equipment to the ground and install the safety bar on the frame. If this is not possible, insert the safety pin or use blocks to prevent the work equipment from falling. In addition, be sure to lock all the control levers and hang warning signs on them. 3. When disassembling or assembling, support the machine with blocks, jacks or stands before starting work. 4. Remove all mud and oil from the steps or other places used to get on and off the machine. Always use the handrails, ladders or steps when getting on or off the machine. Never jump on or off the machine. If it is impossible to use the handrails, ladders or steps, use a stand to provide safe footing.

WF550-3 / WF550T-3

00-3

Safety notice

SAFETY

Precautions during work 1. When measuring hydraulic pressure, check that the measuring tool is correctly assembled before taking any measurements. 2. When removing the oil filler cap, drain plug or hydraulic pressure measuring plugs, loosen them slowly to prevent the oil from spurting out. Before disconnecting or removing components of the oil, water or air circuits, first remove the pressure completely from the circuit. 3. The water and oil in the circuits are hot when the engine is stopped, so be careful not to get burned. Wait for the oil and water to cool before carrying out any work on the oil or water circuits. 4. Before starting work, remove the leads from the battery. Always remove the lead from the negative (-) terminal first. 5. When raising heavy components, use a hoist or crane. Check that the wire rope, chains and hooks are free from damage. Always use lifting equipment which has ample capacity. Install the lifting equipment at the correct places. Use a hoist or crane and operate slowly to prevent the component from hitting any other part. Do not work with any part still raised by the hoist or crane. 6. When removing covers which are under internal pressure or under pressure from a spring, always leave two bolts in position on opposite sides. Slowly release the pressure, then slowly loosen the bolts to remove. 7. When removing components, be careful not to break or damage the wiring. Damaged wiring may cause electrical fires. 8. When removing piping, stop the fuel or oil from spilling out. If any fuel or oil drips onto the floor, wipe it up immediately. Fuel or oil on the floor can cause you to slip, or can even start fires. 9. As a general rule, do not use gasoline to wash parts. In particular, use only the minimum of gasoline when washing electrical parts. Do not smoke! 10. Be sure to assemble all parts again in their original places. Replace any damaged parts with new parts. When installing hoses and wires, be sure that they will not be damaged by contact with other parts when the machine is being oper ated. 11. When installing high pressure hoses, make sure that they are not twisted. Damaged tubes are dangerous, so be extremely careful when installing tubes for high pressure circuits. Also, check that connecting parts are correctly installed.

00-4

WF550-3 / WF550T-3

SAFETY

Safety notice

12. When aligning two holes, never insert your fingers or hand. Be careful not to get your fingers caught in a hole. 13. When assembling or installing parts, always use the specified tightening torques. When installing protective parts such as guards, or parts which vibrate violently or rotate at high speed, be particularly careful to check that they are installed correctly.

WF550-3 / WF550T-3

00-5

Foreword

SAFETY

Foreword General This shop manual has been prepared as an aid to improve the quality of repairs by giving the service personnel an accurate understanding of the product and by showing them the correct way to perform repairs and make judgements. Make sure you understand the contents of this manual and use it to full effect at every opportunity. This shop manual mainly contains the necessary technical information for operations performed in a service workshop. For ease of understanding, the manual is divided into the following chapters; these chapters are further divided into the each main group of components: Structure and function This section explains the structure and function of each component. It serves not only to give an understanding of the structure, but also serves as reference material for troubleshooting. Testing and adjusting This section explains checks to be made before and after performing repairs, as well as adjustments to be made at completion of the checks and repairs. Troubleshooting charts correlating "Problems" to "Causes" are also included in this section. Disassembly and assembly This section explains the order to be followed when removing, installing, disassembling or assembling each component, as well as precautions to be taken for these operations. Maintenance standard This section gives the judgement standards when inspecting disassembled parts.

NOTE The specifications contained in this shop manual are subject to change at any time and without any advance notice. Use the specifications given in the book with the latest date.

00-6

WF550-3 / WF550T-3

SAFETY

How to read the shop manual

How to read the shop manual Volumes Shop manuals are issued as a guide to carrying out repairs.

Distribution and updating Any additions, amendments or other changes will be sent to Komatsu distributors. Get the most up-to-date information before you start any work.

Filing method 1. See the page number on the bottom of the page. File the pages in correct order. 2. Following examples show how to read the page number. Example 1 (Chassis volume): 10 - 3 Item number (10. Structure and Function) Consecutive page number for each item

3. Additional pages: Additional pages are indicated by a hyphen (-) and number after the page number. File as in the example. Example: 10-4 10-4-1 10-4-2 10-5

Added Pages

WF550-3 / WF550T-3

00-7

How to read the shop manual

SAFETY

Symbols So that the shop manual can be of ample practical use, important safety and quality portions are marked with the following symbols: Symbol

Item

a

Safety

Remarks

Special safety precautions are necessary when performing the work.

Caution

Special technical precautions or other precautions for preserving standards are necessary when performing the work.

Weight

Weight of parts of systems. Caution necessary when selecting hoisting wire, or when working posture is important, etc.

Tightening torque

Coat

Oil, water

Drain

00-8

Places that require special attention for the tightening torque during assembly.

Places to be coated with adhesives and libricants, etc.

Places where oil, water or fuel must be added, and the capacity.

Places where oil or water must be drained, and quantity to be drained.

WF550-3 / WF550T-3

SAFETY

Hoisting instructions


Heavy parts (25kg or more) must be lifted with a hoist, etc. In the DISASSEMBLY AND ASSEMBLY section, every part weigthing 25 kg or more is indicated clearly with the symbol:

4

If a part cannot be smoothly removed from the machine by hoisting, the following checks should be made: 1. Check for removal of all bolts fastening the part to the relative parts. 2. Check for existence of another part causing interference with the part to be removed. Wire ropes 1. Use adequate ropes depending on the weight of parts to be hoisted, refering to the table below: •

The allowable load in tons, is given by vertical tensible force.

•

The allowable load value is estimated to be one-sixth or one-seventh of the breaking strength of the rope used. Wire ropes: (Standard "Z" or "S" twist ropes without galvanizing) Rope diameter (mm)

Allowable load (tons)

10

1.0

11.2

1.4

12.5

1.6

14

2.2

16

2.8

18

3.6

20

4.4

22.4

5.6

30

10.0

40

18.0

50

28.0

60

40.0

WF550-3 / WF550T-3

00-9


SAFETY

2. Sling wire ropes from the middle portion of the hook. Slinging near the edge of the hook may cause the rope to slip off the hook during hoisting, and a serious accident can result. Hooks have maximum strength at the middle portion.

100%

88%

79%

71%

41%

3. Do not sling a heavy load with one rope alone, but sling with two or more ropes symmetrically wound onto the load.

Slinging with one rope may cause turning of the load during hoisting, untwisting of the rope, or slipping of the rope from its original winding position on the load, which can result in a dangerous accident.

4. Do not sling a heavy load with ropes forming a wide hanging angle from the hook. When hoisting a load with two or more ropes, the force subjected to each rope will increase with the hanging angles. The table below shows the variation of allowable load (kg) when hoisting is made with two ropes, each of which is allowed to sling up to 1000 kg vertically, at various hanging angles. When two ropes sling a load vertically, up to 2000 kg of total weight can be suspended. This weight becomes 1000 kg when two ropes make a 120° hanging angle. On the other hand, two ropes are subjected to an excessive force as large as 4000 kg if they sling a 2000 kg load at a lifting angle of 150°.

α

Load Capacity (kg) Gewicht (kg) Load capacity (kg)

kg 2000

1900 1700

2000

1400 1000 1000 500

300

600

900

1200

1500

Lifting angle Hebewinkel (°) (°) (α) Lifting Angle

00-10

WF550-3 / WF550T-3

01 GENERAL Specifications . . . . . . . . . . . . . . . . . . . . . . . . . 01-2 WF550-3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 01-2 WF550T-3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 01-4 Weight table . . . . . . . . . . . . . . . . . . . . . . . . . . 01-6 WF550-3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 01-6 WF550T-3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 01-7

WF550-3 / WF550T-3

01-1

Specifications

GENERAL

Specifications

Weight

WF550-3 Machine model

WF550-3

Serial No

50001 and up

Operating weight

kg

Distribution (front)

kg

Distribution (rear)

kg

Bucket capacity (piled)

m3

Rated load

Performance

Travel speed

kN {kg} FORWARD 1st

km/h

6.7

FORWARD 2nd

km/h

12.0

FORWARD 3rd

km/h

20.2

FORWARD 4th

km/h

33.0

REVERSE 1st

km/h

7.5

REVERSE 2nd

km/h

13.4

REVERSE 3rd

km/h

22.5

REVERSE 4th Max. rimpull

km/h

36.1

FORWARD

kN {kg}

274.6 {28,000}

REVERSE

kN {kg}

251.1 {25,600}

deg

25

Gradeability Min. turning radius

Center of outside wheel

mm

Outside portion of chassis (with tooth)

mm

Model

S6D140E-2D

Type

4-cycle, water-cooled, in-line, 6-cylinder, direct injection, with turbocharger

No. of cylinders-bore × stroke

mm

6-140 × 165

Piston displacement

l {cc}

15.2 {15,200}

Performance

Engine

Flywheel horsepower

kW/rpm {HP/rpm}

235/2,100 {315/2,100}

Nm/rpm {kgm/rpm}

1,373/1,400 {140/1,400}

g/kW·h {g/HP·h}

207 {154}

High idling speed

rpm

2,300

Low idling speed

rpm

725

Maximum torque Fuel consumption ratio

Starting motor Alternator Battery

Power train

Torque converter

01-2

Transmission Reduction gear

24V 11kW 24V 50A 12V 170Ah × 2 3-element, 1-stage, single-phase (TCA40-1C) Planetary gear, constant-mesh multiple-disc, hydraulically actuated, modulation type Spiral bevel gear, splash lubrication

Differential

Straight bevel gear

Final drive

Planetary gear single stage, splash lubrication

WF550-3 / WF550T-3

Wheels, rims

GENERAL

Specifications

Machine model

WF550-3

Serial No

50001 and up

Drive type

Front/rear-wheel drive

Front axle

Fixed-frame, full-floating

Rear axle

Center pin support type, full-floating

Shape of front and rear rims Number of feet (Per rim)

Steering system

Brakes

Balance capacity (Per rim)

mm Piece l Front/rear wheel braking, separate front/rear wheel, wet disc, hydraulically actuated

Main brake

Drive shaft, wet type disc brake Hydraulically released spring type

Parking brake Type

Articulated type

Structure

Hydraulic pump Delivery

Fully hydraulically power steering

Work equipment pump

l/min

348 (Gear type: SAR(4) - 160)

Switch pump

l/min

135 (Gear type: SAR(3) - 63)

Steering pump

l/min

172 (Gear type: SAR(3) - 80)

PPC, brake pump

l/min

60 (Gear type: SAR(1) - 28)

Hydraulic system

Main control valve Set pressure

2-spool type MPa {kg/cm2}

20.6 {210}

Control valve Steering valve Set pressure

Spool type MPa {kg/cm2}

Steering cylinder No. - bore × stroke

20.6 {210} Reciprocating piston

mm

Boom cylinder

2 - 110 - 486 Reciprocating piston

Cylinder No. - bore × stroke

mm

Bucket cylinder

Work equipment

No. - bore × stroke Link type

2 - 200 × 839 Reciprocating piston

mm

1 - 225 × 613 Single link

Bucket edge type

WF550-3 / WF550T-3

01-3

Specifications

GENERAL

Weight

WF550T-3 Machine model

WF550-T3

Serial No

50001 and up

Operating weight

kg

Distribution (front)

kg

Distribution (rear)

kg

Performance

Travel speed

Max. rimpull

FORWARD 1st

km/h

6.7

FORWARD 2nd

km/h

12.0

FORWARD 3rd

km/h

20.2

FORWARD 4th

km/h

33.0

REVERSE 1st

km/h

7.5

REVERSE 2nd

km/h

13.4

REVERSE 3rd

km/h

22.5

REVERSE 4th

km/h

36.1

FORWARD

kN {kg}

274.6 {28,000}

REVERSE

kN {kg}

251.1 {25,600}

deg

25

Center of outside wheel

mm

6,160

Outside portion of chassis

mm

7,390

Gradeability

Model

S6D140E-2D

Type

4-cycle, water-cooled, in-line, 6-cylinder, direct injection, with turbocharger

No. of cylinders-bore × stroke

mm

6-140 × 165

Piston displacement

l {cc}

15.2 {15,200}

Flywheel horsepower

kW/rpm {HP/rpm}

235/2,100 {315/2,100}

Maximum torque

Nm/rpm {kgm/rpm}

1,373/1,400 {140/1,400}

g/kW·h {g/HP·h}

207 {154}

High idling speed

rpm

2,300

Low idling speed

rpm

725

Performance

Engine

Min. turning radius

Fuel consumption ratio

Starting motor Alternator Battery

Power train

Torque converter

01-4

Transmission Reduction gear

24V 11kW 24V 50A 12V 170Ah × 2 3-element, 1-stage, single-phase (TCA40-1C) Planetary gear, constant-mesh multiple-disc, hydraulically actuated, modulation type Spiral bevel gear, splash lubrication

Differential

Straight bevel gear

Final drive

Planetary gear single stage, splash lubrication

WF550-3 / WF550T-3

Wheels, rims

GENERAL

Specifications

Machine model

WF550-T3

Serial No

50001 and up

Drive type

Front/rear-wheel drive

Front axle

Fixed-frame, full-floating

Rear axle

Center pin support type, full-floating

Shape of front and rear rims Number of feet (Per rim)

Steering

Brakes

Balance capacity (Per rim)

Piece l Front/rear wheel braking, separate front/rear wheel, wet disc, hydraulically actuated

Main brake

Drive shaft, wet type disc brake Hydraulically released spring type

Parking brake Type

Articulated type

Structure

Hydraulic pump Delivery

Hydraulic system

mm

Fully hydraulically power steering Work equipment pump

l/min

172 (Gear type: SAR(3) - 80)

Switch pump

l/min

135 (Gear type: SAR(3) - 63)

Steering pump

l/min

172 (Gear type: SAR(3) - 80)

PPC, brake pump

l/min

60 (Gear type: SAR(1) - 28)

Main control valve Set pressure

2-spool type MPa {kg/cm2}

20.6 {210}

Control valve Steering valve Set pressure

Spool type 2

MPa {kg/cm }

Steering cylinder No. - bore × stroke

20.6 {210} Reciprocating piston

mm

2 - 110 - 486

Cylinder Lift cylinder

Dozing equipment

No. - bore × stroke

Reciprocating piston mm

Blade width

mm

Blade height

mm

Max. lift above ground

mm

Max. drop below ground

mm

WF550-3 / WF550T-3

1 - 140 × 1020

01-5

Weight table

GENERAL

Weight table

This weight table is a guide for use when transporting or handling components.

WF550-3 Unit: kg Machine model

WF550-3

Machine model

WF550-3

Serial Number

50001 and up

Serial Number

50001 and up

Engine assembly

1,520

Hydraulic pump

20.3

Radiator assembly

300

Switch and PPC pumps

19

Torque converter assembly

215

Steering pump

12.2

Transmission assembly

930

PPC valve

3.5

Damper

91

Main control valve

90

Upper drive shaft

18

Lift cylinder

272

Center drive shaft

33

Bucket cylinder

286

Front drive shaft

45

Engine hood

225

Rear drive shaft

41

Front frame

2,274

Center support

42

Rear frame

2,530

Front axle assembly

2,480

Bucket link (with bushing)

106

Rear axle assembly

2,241

Bellcrank (with bushing)

522

Front differential assembly

268

Boom (with bushing)

Rear differential assembly

272

Bucket (with teeth)

Planetary carrier assembly (1 piece)

62

Rear bamper

440

Wheel hub assembly (1 piece)

147

Fuel tank

313

Battery (1 piece)

53

Cab assembly

355

Axle pivot (Rear axle)

94/114

Steel wheel (1 piece) Steering valve

23.5

Air conditioner unit

28

Orbit-roll valve

5.2

Operator’s seat

39

Steering cylinder (1 piece)

47

Floor, dash, console

214

Brake valve (Tandem)

8.5

Brake valve (Single)

5.3

Hydraulic tank

290

01-6

WF550-3 / WF550T-3

GENERAL

Weight table

WF550T-3 Unit: kg Machine model

WF550T-3

Machine model

WF550T-3

Serial Number

50001 and up

Serial Number

50001 and up

Engine assembly

1,520

Hydraulic pump

12.2

Radiator assembly

300

Switch and PPC pumps

19

Torque converter assembly

215

Steering pump

12.2

Transmission assembly

930

PPC valve

3.5

Damper

91

Main control valve

71

Upper drive shaft

18

Lift cylinder

149

Center drive shaft

33

Engine hood

225

Front drive shaft

45

Front frame

2,638

Rear drive shaft

41

Rear frame

2,530

Center support

42

Blade

Front axle assembly

2,377

Rear damper

440

Rear axle assembly

2,241

Fuel tank

313


268

Battery (1 piece)

53


280

Cab assembly

355

Planetary carrier assembly (1 piece)

62

Air conditioner unit

28

Wheel hub assembly (1 piece)

147

Operator’s seat

39

Floor, dash, console

214

Axle pivot (Rear axle)

94/114

Steel wheel (1 piece) Steering valve

23.5

Orbit-roll valve

5.2

Steering cylinder (1 piece)

47

Brake valve (Tandem)

8.5

Brake valve (Single)

5.3

Hydraulic tank

290

WF550-3 / WF550T-3

01-7

Weight table

GENERAL

Blank for technical reason

01-8

WF550-3 / WF550T-3

10 STRUCTURE AND FUNCTION General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-4

Parking brake . . . . . . . . . . . . . . . . . . . . . . . . . . . . ★

Drive unit cooling fan . . . . . . . . . . . . . . . . . . 10-7 Hydraulic motor . . . . . . . . . . . . . . . . . . . . . . . . 10-7 Cooling fan controller . . . . . . . . . . . . . . . . . . . . 10-8 Forward/reverse timer . . . . . . . . . . . . . . . . . . . 10-9 Electromagnetic selector valve . . . . . . . . . . . 10-10

Parking brake solenoid valve . . . . . . . . . . . . . . . ★

Damper. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .★ Torque converter and transmission piping . . . .★ Torque converter and PTO. . . . . . . . . . . . . . . . . . ★ Transmission . . . . . . . . . . . . . . . . . . . . . . . . 10-14 Transmission control valve . . . . . . . . . . . . . . . . . ★

Parking brake emergency release solenoid valve . . . . . . . . . . . . . . . . . . . . . . . . 10-55 Hydraulic piping . . . . . . . . . . . . . . . . . . . . . . . 10-56 Work equipment lever linkage . . . . . . . . . . .10-57 WF550T-3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-57 WF550-3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-58 Hydraulic tank . . . . . . . . . . . . . . . . . . . . . . . . 10-59 Accumulator (for PPC valve) . . . . . . . . . . . . . . . . ★

Main relief, torque converter relief valve . . 10-20 Operation of main relief valve . . . . . . . . . . . . 10-22 Operation of torque converter relief valve . . . 10-23

PPC valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-61 WF550T-3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-61 WF550-3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-63 Operation of PPC valve . . . . . . . . . . . . . . . . . . 10-65 Function of PPC valve . . . . . . . . . . . . . . . . . . .10-66

Lubricating relief valve . . . . . . . . . . . . . . . . . . . . .★

PPC relief valve. . . . . . . . . . . . . . . . . . . . . . . . . . . ★

ECMV (Electronic Control Modulation Valve). . .★

Torque converter oil filter. . . . . . . . . . . . . . . . . . . ★ Pilot filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ★ Transfer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .★ Drive shaft . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ★ Center support . . . . . . . . . . . . . . . . . . . . . . . . . . .★ Axle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-30 Front . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-30 Rear . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-31 Differential . . . . . . . . . . . . . . . . . . . . . . . . . . 10-32 Front differential . . . . . . . . . . . . . . . . . . . . . . . 10-32 Rear differential . . . . . . . . . . . . . . . . . . . . . . . 10-32 Limited slip differential . . . . . . . . . . . . . . . . 10-34 Final drive . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-38 Axle mount, center hinge pin . . . . . . . . . . . 10-39 Steering piping . . . . . . . . . . . . . . . . . . . . . . . 10-40 Steering column . . . . . . . . . . . . . . . . . . . . . . . . . .★ Steering valve . . . . . . . . . . . . . . . . . . . . . . . . . . . .★ Orbit-roll valve. . . . . . . . . . . . . . . . . . . . . . . . . . . .★ Stop valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ★ Brake piping . . . . . . . . . . . . . . . . . . . . . . . . . 10-45 Brake valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ★ Charge valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . .★ Accumulator (for brake) . . . . . . . . . . . . . . . . . . . .★

Cut-off valve . . . . . . . . . . . . . . . . . . . . . . . . . .10-69 WF550-3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-69 Operation of cut-off valve . . . . . . . . . . . . . . . . . 10-70 Main control valve . . . . . . . . . . . . . . . . . . . . .10-71 WF550T-3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-71 WF550-3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-73 Main relief valve . . . . . . . . . . . . . . . . . . . . . . . 10-75 WF550T-3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-75 WF550-3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-76 Safety valve (with suction) . . . . . . . . . . . . . . . . 10-77 Suction valve . . . . . . . . . . . . . . . . . . . . . . . . .10-79 Float selector valve and unload valve . . . . .10-80 WF550-3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-80 Operation (WF550T-3) . . . . . . . . . . . . . . . . . . 10-82 Lift spool hold position . . . . . . . . . . . . . . . . . . .10-82 Lift spool at raise position . . . . . . . . . . . . . . . . 10-84 Lift spool at lower position . . . . . . . . . . . . . . . . 10-86 Lift spool at float position . . . . . . . . . . . . . . . . . 10-88 Operation (WF550-3) . . . . . . . . . . . . . . . . . . .10-90 Boom and bucket spool hold position . . . . . . .10-90 Boom spool at raise position . . . . . . . . . . . . . .10-92 Boom spool at lower position . . . . . . . . . . . . . .10-94 Boom spool at float position . . . . . . . . . . . . . . . 10-96 Bucket spool at dump position . . . . . . . . . . . . .10-98 Bucket spool at tilt position . . . . . . . . . . . . . . 10-100 Bucket positioner and boom kick-out (WF550-3) . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-102

Slack adjuster . . . . . . . . . . . . . . . . . . . . . . . . . . . .★

Air conditioner . . . . . . . . . . . . . . . . . . . . . . . 10-107 Air conditioner piping . . . . . . . . . . . . . . . . . . .10-107

Brake . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-50

Machine monitor system . . . . . . . . . . . . . . . 10-108

Parking brake control . . . . . . . . . . . . . . . . . . . . . .★

Main monitor . . . . . . . . . . . . . . . . . . . . . . . .10-110

WF550-3 / WF550T-3

10-1

Main monitor display function . . . . . . . . . . . . Main monitor switch function . . . . . . . . . . . . Preheating output function . . . . . . . . . . . . . . Trouble data display mode (when optional controller are installed) . . . . Maintenance monitor . . . . . . . . . . . . . . . . . Maintenance monitor display function . . . . . All-Range Electronic Control Automatic Transmission System . . . . . . . . . . . . . . . . . System structure diagram . . . . . . . . . . . . . . Transmission controller power source . . . . . Input signals . . . . . . . . . . . . . . . . . . . . . . . . . Output signals . . . . . . . . . . . . . . . . . . . . . . . LED display . . . . . . . . . . . . . . . . . . . . . . . . .

10-112 10-113 10-113 10-114 10-116 10-118 10-119 10-120 10-126 10-127 10-130 10-132

Transmission controller . . . . . . . . . . . . . . 10-134 Connector signals . . . . . . . . . . . . . . . . . . . . 10-135 Sensors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .★ Engine starting circut . . . . . . . . . . . . . . . . . . . . . .★ Engine stop circut. . . . . . . . . . . . . . . . . . . . . . . . . ★ Preheating circut (automatic preheating system) . . . . . . . . . . . . . .★ Electric transmission control . . . . . . . . . . 10-140 Combination switch . . . . . . . . . . . . . . . . . . . 10-142 Kick-down, hold switch . . . . . . . . . . . . . . . . . . . .★ Electric parking brake control . . . . . . . . . . . . . . .★

As for structure and function, enter only the special section of WF550 and WF550T-3. Do not enter the sections common to WA500-3.

The sections common to WA500-3 are marked with ★ in the Page No. column on the table of contents. For those sections, see WA500-3 Shop Manual.

10-2

WF550-3 / WF550T-3

STRUCTURE AND FUNCTION


WF550-3 / WF550T-3

10-3

General


General WF550-3

WF550T-3

10-4

WF550-3 / WF550T-3


General

1. Center drive shaft 2. Transmission 3. Torque converter 4. Upper drive shaft 5. Damper 6. Engine 7. Rear differential 8. Rear drive shaft 9. Parking brake 10. Front drive shaft 11. Front differential

Outline •

The power from engine (6) is transmitted from the flywheel to damper (5) through the ring gear. The damper alleviates the torsional vibration caused by the variation of the engine torque and transmits the power to torque converter (3) through drive shaft (4). The torque converter converts the delivered torque according to the variation in load on the oil used as the medium, and transmits the power to the input shaft of transmission (2). Then, the engine power is transmitted to PPC pump and steering pump, hydraulic pump, switch pump, and torque converter charging pump through the pump driving gear in torque converter (3), thereby driving the pumps.

•

In transmission (2), the six hydraulically-operated clutches are operated by the forward-reverse spool and the speed change spools in the transmission valves, which are themselves activated by solenoid valves. Thus, the desired travel speed can be selected from among the 4 forward and 4 reverse gear speeds.

•

A multiple disc parking brake is installed to the output shaft of transmission (2). At the front end, the power from the output shaft passes through center drive shaft (1) and front drive shaft (10) and is transmitted to front differential (11); at the rear end it is transmitted to rear differential (7) by rear drive shaft (8).

•

The power transmitted to front differential (11) and rear differential (7) is transmitted to the axle shafts.

•

The power from the axle shafts has its speed reduced by final drives, and it is then transmitted to wheels through the planetary carrier.

WF550-3 / WF550T-3

10-5

General


1.

Engine

2.

Damper

10. Transmission

18. Front wheel

3.

Upper drive shaft

11. Parking brake

19. Rear drive shaft

4.

Torque converter

12. Center drive shaft

20. Rear differential

5.

Torque converter charging pump

13. Center support

21. Rear final drive

6.

Switch pump

14. Front drive shaft

22. Rear brake

7.

PPC pump

15. Front differential

23. Rear wheel

8.

Hydraulic pump

16. Front final drive

10-6

9. Steering pump

17. Front brake

WF550-3 / WF550T-3


Drive unit cooling fan

Drive unit cooling fan •

The cooling fan of the radiator is driven with a hydraulic motor.

•

It can be revolved in reverse to remove dirt from the radiator core in the jobsite by operating the auto/manual selector switch and forward/reverse timer.

Hydraulic motor

Specifications Type:

Vane motor M5BF

Capacity:

45 cc/rev

Rated pressure:

14.7 MPa {150 kg/cm²}

Revolving direction Inlet A:

Clockwise

Revolving direction Inlet B:

Counterclockwise

Tightening torque of fan mounting bolt:

245 ± 29 Nm {25 ± 3 kgfm}

WF550-3 / WF550T-3

10-7



Cooling fan controller WF 550-3

WF 550T-3

1.

Auto/Manual selector switch

4.

Forward/Reverse selector switch

2.

Control box

5.

Work equipment control lever

3.

Reverse pilot lamp

6.

Forward/reverse timer

10-8

WF550-3 / WF550T-3



Forward/reverse timer This timer operates only when the AUTO / MANUAL selector switch is at the AUTO position Forward lamp (Green) (Lights up during forward revolution) Reverse lamp (Green) (Lights up during forward revolution)

Scale figure indicator window Scale figure selector switch (Common to reverse time and forward time)

Forward time unit indicator window Forward time unit selector switch Reverse setting dial (Orange pointer) (Used to set reverse time) Reverse setting dial (Orange pointer) (Used to set reverse time) Reverse time unit indicator window Reverse time unit selector switch

NOTE When setting the timer, be sure to turn off the starting switch. ★ Each time the cooling fan changes its revolving direction, it continues revolving by inertia in the current direction for 10 – 15 seconds before starting revolving in the opposite direction to lower the impact caused by the change of its revolving direction and protect the hydraulic circuit. When the starting switch of the cooling fan is turned on or when the cooling fan changes its revolving direction, the fan takes 10 – 15 seconds to start revolving forward or change its revolving direction. This does not indicate a trouble.

WF550-3 / WF550T-3

10-9



Electromagnetic selector valve

From Priority Valve

1.

Electromagnetic selector valve

2.

Anti-cavitation modular valve

3.

Block

10-10

WF550-3 / WF550T-3


Pages 10-11 to 10-13 skipped for technical reason

WF550-3 / WF550T-3

Transmission


Transmission

1.

Main relief, torque converter relief valve

6. Parking brake

2.

Transmission valve

7. Output coupling (front)

3.

Transmission input shaft

8. Output coupling (rear)

4.

Transmission

9. Oil filler port

5.

Transfer

10-14

10. Strainer

WF550-3 / WF550T-3


Transmission

Vale mount surface

A.

To torque converter

B.

From torque converter case

C.

Breather mount port

J.

To torque converter charging pump

D.

From oil filter

K.

To REVERSE clutch

E.

Transmission main oil pressure port

L.

To 3rd clutch

F.

To parking brake emergency release valve

M.

To 1st clutch

G.

Lubricating oil pressure port

N.

To 2nd clutch

H.

From oil cooler

O.

To 4th clutch

P.

To FORWARD clutch

WF550-3 / WF550T-3

I.

Mounting port for parking brake actuation pilot lamp

10-15

Transmission

10-16


WF550-3 / WF550T-3


Transmission

1. Input shaft

16. No. 4 clutch

2. No. 1 sun gear (No. of teeth: 22)


3. No. 1 planet gear (No. of teeth: 24)


4. No. 1 ring gear (No. of teeth: 90)


5. No. 1 clutch

20. No. 5 clutch

6. No. 1 idler gear (No. of teeth: 70)

21. No. 6 gear (No. of teeth: 90)

7. Lubrication relief valve

22. No. 6 clutch

8. No. 2 clutch

23. Output shaft

9. No. 3 sun gear (No. of teeth: 15) (Output shaft)

24. No. 5 carrier


25. No. 3, 4 carrier

11. No. 3 clutch





28. No. 2 carrier


29. No. 1 carrier



Number of clutch discs and plates Clutch No.

Disc

Plate

No. 1

4

4+1

No. 2

4

4+1

No. 3

3

2

No. 4

3

2+1+1

No. 5

3

2+1

No. 6

3

2

★ For each clutch and explanation of operation, see WA500-3 Shop Manual.

WF550-3 / WF550T-3

10-17



WF550-3 / WF550T-3



WF550-3 / WF550T-3




1.

Body

A. Drain port (torque converter relief)

2.

Torque converter relief valve

B. Drain port

3.

Valve spring

C. From pump

4.

Piston

D. Drain port

5.

Piston spring

E. To torque converter

6.

Main relief valve

P1. Main relief oil pressure detection port

7.

Valve spring

P2. Torque converter relief oil pressure detection port

8.

Piston spring

9.

Piston

10-20

WF550-3 / WF550T-3



Outline 1. Main relief valve Main relief valve (6) sets the set pressure of the transmission oil. 2. Torque converter relief valve Torque converter relief valve (2) acts to protect the torque converter from abnormally high pressure. It relieves the pressure when the pressure at the inlet port of the torque converter goes above the specified pressure. Unit MPa {kg/cm²} Specified pressure Main relief pressure

3.52 {35.9} (engine at rated speed)

Torque converter inlet port pressure

0.84 {8.5} (cracking pressure)

WF550-3 / WF550T-3

10-21



Operation of main relief valve •

The oil from the torque converter charging pump passes through the filter, enters port A of the main relief valve, and then passes through orifice a and enters port B.

•

When the oil from the pump fills the circuit, the oil pressure starts to rise.

•

When the oil pressure in the circuit rises, the oil entering port B pushes piston (4). The reaction compresses spring (7) and moves main relief valve (6) to the left to open the passage between port A and port C.

•

When this happens, the oil from the pump is relieved from port A to port C, and flows from port C into the torque converter.

•

The oil pressure at port A at this point is 3.52 MPa {35.9 kg/cm²} (engine at rated speed).

To torque converter

To T/M lubrication

From pump

10-22

WF550-3 / WF550T-3



Operation of torque converter relief valve •

The oil relieved from the main relief valve flows from port C into the torque converter, and at the same time, passes through orifice b and enters port D.

•

When the oil fills the circuit to the torque converter, the oil pressure starts to rise.

To torque converter

To T / M lubrication

From pump

•

When the oil pressure in the circuit to the torque converter rises, the oil entering port D pushes piston (9). The reaction compresses spring (3), and moves relief valve (2) to the right to open the passage between port C and port E.

•

When this happens, the oil from port C is relieved to port E and flows to the transmission lubrication circuit.

•

The oil pressure at port C at this point is 0.84 MPa {8.5 kg/ cm²} (cracking pressure).

To torque converter

To T / M lubrication

From pump

WF550-3 / WF550T-3

10-23



WF550-3 / WF550T-3



WF550-3 / WF550T-3

Axle


Axle Front

1.

Filler

5.

Front brake

2.

Level plug

6.

Final drive

3.

Front differential

7.

Drain plug

4.

Front axle

10-30

WF550-3 / WF550T-3


Axle

Rear

1.

Level plug

5.

Rear brake

2.

Rear axle

6.

Final drive

3.

Filler

7.

Drain plug

4.

Rear differential

WF550-3 / WF550T-3

10-31

Differential


Differential Front differential

1.

Bevel gear (No. of teeth: 42)

2.

Bevel pinion (No. of teeth: 9)

2.

Bevel pinion (No. of teeth: 9)

Rear differential

1.

Bevel gear (No. of teeth: 42)

10-32

WF550-3 / WF550T-3


Differential

Outline •

The motive force from the engine is transmitted to the front and rear axles via the torque converter, the transmission and the drive shaft.

•

The motive force from the drive shaft passes through bevel pinion (1) and is transmitted to bevel gear (2). The bevel gear changes the direction of the motive force by 90°, and at the same time reduces the speed. It then transmits the motive force through differential (3) to axle shaft (4).

•

The final drive of planetary gear type reduces the speed of the motive force of the axle shaft and transmits it to the rims.

WF550-3 / WF550T-3

10-33

Limited slip differential



1.

Plate

7. Pinion

2.

Disc

8. Shaft

3.

Washer

9. Pressure ring

4.

Shaft

10. Case

5.

Cover

11. Bevel pinion

6.

Side gear

10-34

WF550-3 / WF550T-3



Operation of limited slip differential The power transmitted from the transmission goes from bevel gear (11) to case (10), pressure ring (9), shaft (8), pinion (7), and gear (6), and is then divided and sent left and light shafts (4). A brake mechanism consisting of disc (2) and plate (1) is assembled at the rear face of side gear (6), and the brake torque is generated in proportion to the torque transmitted from pressure ring (9) to shaft (8). In order for this brake torque to act to suppress the rotation in relation to side gear (6) and case (10), it is made difficult for left and right side gears (6) to rotate mutually, and the action of the differential is suppressed.

Mechanism for generation of brake torque of left and right side gears (6) Shaft (8) is supported by the cam surface cut into the mating surfaces of left and right pressure rings (9). The power (= torque) transmitted from pressure ring (9) to shaft (8) is transmitted by the cam surface, but force Fa to separate left and right pressure rings (9) is generated in proportion to the torque transmitted by the angle of this cam surface. This separation load Fa acts as a brake on the rear face of left and right side gears (6) and generates brake torque. View Z from previous page

WF550-3 / WF550T-3

10-35



When travelling in straight line 1. When there is no imbalance between drive force of left and right wheels •

[The road surface condition (friction coefficient) for the left and right wheels and the load on the wheels are uniform, so there is no misalignment of the center line of the load to the bucket]

•

The power from the transmission is divided uniformly to the left and right by the limited slip differential. Under these conditions, the limit for wheel slip for the left and right wheels is the same, so even if the power from the transmission exceeds the wheel slip limit, the wheels on both sides slip and the differential is not actuated.

•

No load is applied to the brake at the rear surface of the side gear.

From transmission

2. When there is imbalance between drive force of left and right wheels Brake torque

[The road surface condition (friction coefficient) for the left and right wheels and the load on the wheels are not uniform and the wheel on one side tends to slip more than the wheel on the other side.] Example 1: When wheel on one side is on soft ground surface during digging operations Example 2: When wheel on one side is on asphalt surface and wheel on other side is on snow during snow-clearing operations Example 3: When imbalance is created in load on left and right wheels by traveling on slope The power from the transmission is divided uniformly to the left and right by the actuating gear. However, if the divided drive force exceeds the wheel slip limit on the side where the wheel is slipping, a drive force equal to the excess is sent through the brake at the rear face of the side gear and the case to the brake on the opposite side (side where wheel is locked), and is supplied to the wheel on the side which is locked.

Side where wheel is slipping

Side where wheel is locked

From transmission

If this excess drive force becomes greater than the braking force, the differential starts to be actuated.

10-36

WF550-3 / WF550T-3



Difference in wheel drive force for each type of differential when wheel on one side is slipping. Wheel drive force (taken as 1 for wheel that is slipping) Slipping wheel

Locked wheel

Tortal (proportional)

Limited slip differential (option)

1

2.64

3.64 (1.53)

Torque proportioning differential (standard)

1

1.38

2.38 (1)

1

1

2 (0.84)

Normal differential

Outside wheel (rotates faster)

Inside wheel (rotates slower)

On road surfaces where the wheel on one side is likely to slip, the limited slip differential increases the drive force 1.53 times that of the torque proportioning differential sipplied as standard.

When turning The actuating gear built into the limited slip differential is the same as the gear used on the normal differential, so the difference in rotation of the inside and outside wheels generated when turning can be generated smoothly.

WF550-3 / WF550T-3

10-37

Final drive


Final drive

1.

Axle shaft

4.

Planetary carrier

2.

Planetary gear (Teeth 44)

5.

Sun gear (Teeth 18)

3.

Ring gear (Teeth 108)

6.

Wheel

Outline To gain a large drive force, the final drive uses a planetary gear system to reduce the speed and send drive force to the tires.

Operation The motive force transmitted from the differential through axle shaft (1) to sun gear (5) is transmitted to planetary gear (2). The planetary gear rotates around the inside of a fixed ring gear (3) and in this way transmits rotation at a reduced speed to the planetary carrier (4). This motive force is then sent to the wheels (6) which are installed to the planetary carriers (4).

10-38

WF550-3 / WF550T-3


Axle mount, center hinge pin

Axle mount, center hinge pin Machine body shows WF550-3.

1.

Front axle

4.

Rear axle

2.

Front frame

5.

Upper hinge pin

3.

Rear frame

6.

Lower hinge pin

Outline The front frame (2) and rear frame (3) are connected through a bearing by the center hinge pin (5), (6). The steering cylinders are connected to the left and right front and rear frames, so when the cylinders are operated, the frame bends at the middle to give the desired angle, that is the desired turning radius.

WF550-3 / WF550T-3

10-39

Steering piping


Steering piping Machine body shows WF550-3.

1.

Steering cylinder (R.H.)

7. Switch pump and PPC pump

2.

Orbit-roll valve

8. Steering pump

3.

Stop valve (R.H.)

9. Stop valve (L.H.)

4.

Hydraulic tank

10. Steering valve

5.

Hydraulic pump

11. Steering cylinder (L.H.)

6.

Oil cooler

10-40

WF550-3 / WF550T-3



WF550-3 / WF550T-3



WF550-3 / WF550T-3


Brake piping

Brake piping Machine body shows WF550-3.

1.

Brake valve (right)

10. Slack adjuster (rear)

2.

Hydraulic tank

11. Rear brake (left)

3.

Parking brake switch

12. PPC pump (also for brake)

4.

Emergency release parking brake switch

13. Transmission control valve

5.

Rear brake (right)

14. Parking brake (built into transmission)

6.

Charge valve

15. Brake valve (left)

7.

Filter

16. Front brake (left)

8.

Accumulator

17. Slack adjuster (front)

9.

Parking brake valve

18. Front brake (right)

WF550-3 / WF550T-3

10-45



WF550-3 / WF550T-3



WF550-3 / WF550T-3

Brake


Brake

1.

Guide pin

5.

Outer gear (No. of teeth: 138)

2.

Return spring

6.

Inner gear (No. of teeth: 105)

3.

Cylinder

7.

Plate

4.

Brake piston

8.

Disc

10-50

WF550-3 / WF550T-3


Brake

Function Main brakes are wet-type multiple-disc brakes and are installed to all four wheels.

Operation •

•

When the brake pedal is depressed, the pressure oil from the brake valve moves brake piston (4) to the right in the direction of the arrow. This brings disc (8) and plate (7) into contact, and friction is generated between the disc and plate. The wheel is rotating together with the disc, so the machine speed is reduced and the machine is stopped by this friction.

When the brake pedal is released, the pressure at the back face of brake piston (4) is released, so the piston is moved to the left in the direction of the arrow by the force of return spring (2), and the brake is released.

WF550-3 / WF550T-3

From slack adjuster

To slack adjuster

10-51



WF550-3 / WF550T-3


Parking brake emergency release solenoid valve

Parking brake emergency release solenoid valve

1.

Valve ass‘y

2.

Solenoid valve

A:

To parking brake

B:

From parking brake valve

C:

From pilot circuit

T:

Drain

P:

From brake (accumulator circuit)

Function The emergency release solenoid valve is installed between the transmission and the transmission control valve. If the engine breaks down and no oil pressure is supplied from the transmission pump, it is possible to actuate the solenoid for the parking brake release switch in the operator’s compartment. This allows the accumulator charge pressure in the brake circuit to flow to the parking brake cylinder.

To parking brake

Parking brake emergency release solenoid

Operation When parking brake emergency release switch ➀ is turned ON, solenoid valve ➁ is actuated and the pressure stored in accumulator ➂ enters from port P. The circuit is switched by the pilot pressure, so the oil flows from port A to the parking brake to release the parking brake.

WF550-3 / WF550T-3

From parking brake valve

Parking brake emergency release switch From brake circuit

10-55

Hydraulic piping


Hydraulic piping Machine body shows WF550-3.

1.

Main control valve

10. Accumulator

2.

Bucket cylinder

11. Radiator

3.

Steering valve

12. Oil cooler

4.

Orbit-Roll

13. Hydraulic pump

5.

Hydraulic tank

14. Steering pump

6.

PPC valve

15. Cut-off valve

7.

Solenoid valve

16. Steering cylinder

8.

Switch, PPC pump

17. Boom cylinder

9.

Check valve

10-56

WF550-3 / WF550T-3


Work equipment lever linkage

Work equipment lever linkage WF550T-3

1.

Lift lever

2.

Safety lever

3.

PPC valve

WF550-3 / WF550T-3

10-57

Work equipment lever linkage


WF550-3

1.

Work equipment lever

2.

Safety lever

3.

PPC valve

10-58

WF550-3 / WF550T-3


Hydraulic tank

Hydraulic tank

1.

Filter bypass valve

A.

PPC, orbit-roll return port

2.

Hydraulic filter

B.

Main return port

3.

Drain valve

C.

Hydraulic cooler return port

4.

Breather

D.

Main suction port

5.

Oil level sight gauge

E.

Emergency steering suction port

6.

Hydraulic tank

F.

Fan motor return port

WF550-3 / WF550T-3

10-59


Page 10-60 skipped for technical reason

WF550-3 / WF550T-3


PPC valve

PPC valve WF550T-3

P.

From PPC pump

P2. To main control valve lift spool

WF550-3 / WF550T-3

P3. To main control valve lift spool T.

Drain

10-61

PPC valve


1.

Bolt

6.

Centering spring

2.

Piston

7.

Metering spring

3.

Plate

8.

Valve

4.

Collar

9.

Body

5.

Retainer

10-62

WF550-3 / WF550T-3


PPC valve

WF550-3

P.

From PPC pump

P3. To RAISE end of main control valve boom spool

P1. To TILT end of main control valve bucket spool

P4. To DUMP end of main control valve bucket spool

P2. To LOWER end of main control valve boom spool

T.

WF550-3 / WF550T-3

Drain

10-63

PPC valve


1.

Bolt

6.

Centering spring

2.

Piston

7.

Metering spring

3.

Plate

8.

Valve

4.

Collar

9.

Body

5.

Retainer

10-64

WF550-3 / WF550T-3


PPC valve

Operation of PPC valve [At neutral]

To cylinder

To tank

To cylinder

From pump

Charge valve

Accumulator

Filter

Check valve

PPC pump

Hydraulic tank

The oil from the PPC pump enters port P of the PPC valve, but the circuit is closed by spool (8), so the oil is drained from relief valve (1). At the same time, the oil at port PA1 of the main control valve is drained from port f of spool (8). In addition, the oil at port PB1 is drained from port g of spool (10).

WF550-3 / WF550T-3

10-65

PPC valve


Function of PPC valve The PPC valve supplies pressure oil from the charging pump to the side face of the spool of each control valve according to the amount of travel of the control lever. This pressure oil actuates the spool.

Operation 1. Control lever at "hold" (Fig. 1): Ports PA1, P4, PB1 and P1 are connected to drain chamber D through fine control hole (f) in valve (8). 2. Control lever operated slightly (fine control) (Fig. 2): When piston (2) starts to be pushed by plate (10), retainer (5) is pushed. Valve (8) is also pushed by spring (7) and moves down. When this happens, fine control hole (f) is shut off from drain chamber D. At almost the same time it is connected to pump pressure chamber PP, and the pilot pressure of the control valve is sent through fine control hole (f) to port P4. When the pressure at port P4 rises, valve (8) is pushed back. Fine control hole (f) is shut off from pump pressure chamber PP. At almost the same time it is connected to drain chamber D, so the pressure at port P4 escapes to drain chamber D.

Control valve

Valve (8) moves up and down until the force of spring (7) is balanced with the pressure of port P4. The position of valve (8) and body (9) (when fine control hold (f) is midway between drain chamber D and pump pressure chamber PP) does not change until the head of valve (8) contacts the bottom of piston (2). Therefore, spring (7) is compressed in proportion to the travel of the control lever, so the pressure at port P4 also rises in proportion to the travel of the control lever. The spool of the control valve moves to a position where the pressure of port PA1 (same as pressure at port P4) and the force of the return spring of the control valve are balanced.

Control valve

10-66

WF550-3 / WF550T-3


PPC valve

3. Control lever moved back from slightly operated position to hold (Fine control) (Fig. 3): When plate (10) starts to be pushed back, piston (2) is pushed up by a force corresponding to the force of centering spring (6) and the pressure at port P4. At the same time, fine control hole (f) of valve (8) is connected to drain chamber D, so the oil at port P4 escapes. If the pressure at port P4 drops too far, valve (8) is pushed down by spring (7). Fine control hole (f) is shut off from drain chamber D, and at almost the same time it is connected to pump pressure chamber PP. The pump pressure is supplied until the pressure at port PA1 returns to a pressure equivalent to the position of the lever. When the spool of the control valve returns, the oil in drain chamber D flows in from fine control hole (f’) of the valve which has not moved. The extra oil then flows through port P1 to chamber PB1.

Control valve

4. Control lever operated to end of travel (Fig. 4): Plate (10) pushes piston (2) down, and piston (2) forcibly pushes in valve (8). Fine control hole (f) is shut off from drain chamber D, and is connected to pump pressure chamber PP. Therefore, pressure oil from the charging pump passes through fine control hole (f), and flows from port P4 to chamber PA1 to push the spool of the control valve. The oil returning from chamber PB1 flows from port P1 through fine control hole (f’) to drain chamber D.

Control valve

WF550-3 / WF550T-3

10-67


Page 10-68 skipped for technical reason

WF550-3 / WF550T-3


Cut-off valve

Cut-off valve WF550-3

1.

Unload valve

C.

Port C (from hydraulic pump)

2.

Check valve

P.

Port P (from steering valve)

3.

Cut-off relief valve

T.

Port T (to tank)

4.

Screen

T1. Port T1 (to tank)

Function •

The cut-off valve is installed between the switch pump and the main control valve. Depending on the operating condition, it switches the oil from the switch pump to the main control valve or to the drain circuit.

•

The cut-off valve is operated by hydraulic pressure.

WF550-3 / WF550T-3

10-69

Cut-off valve


Operation of cut-off valve Work equipment valve

Cut-off operation conditions O: Cut-off (drain) X:

Work equipment pump

Not actuated (to main control valve) More than 17.2 MPa

Less than 17.2 MPa

{175 kg/cm²}

{175 kg/cm²}

Kick-down switch "ON"

O

X

X

Operation 1. When the work equipment valve is held The oil at the switch pump (the oil from the steering valve) presses up check valve (1), merges with the oil from the work equipment pump and flows to the work equipment valve. 2. When the work equipment valve is activated

Steering valve

Steering pump

Switch pump

a. When the work equipment pump pressure is lower than the cut-off pressure Work equipment valve

As when the work equipment valve is held, the oil at the switch pump (the oil from the steering valve) presses up check valve (1), merges with the oil from the work equipment pump and flows to the work equipment valve.

Work equipment pump

b. When the work equipment pump pressure is higher than the cut-off pressure When the cut-off pressure is reached, the pressure of the oil in chamber a opens cut-off valve (2), and the oil in unload valve (3) chamber b passes through cut-off valve (2) chamber c and is drained. The oil in unload valve (3) chamber d passes through orifices e and f, and into chamber b causing the oil pressure in chamber d decrease, and unload valve (3) to open. Thus, the oil from the switch pump is drained. Steering valve

Steering pump

10-70

Switch pump

WF550-3 / WF550T-3


Main control valve

Main control valve WF550T-3

A1. Unused (Plugged)

P1A. Unused (Plugged)

A2. To lift cylinder bottom end

P2A. From PPC valve P3

B1. Unused (Plugged)

P1B. Unused (Plugged)

B2. To lift cylinder head end

P2B. From PPC valve P2

P1. From pump

T.

WF550-3 / WF550T-3

Drain port

10-71

Main control valve


1.

Tilt spool return spring

5.

Body

2.

Lift spool return spring

6.

Suction valve

3.

Lift spool

7.

Safety valve with suction

4.

Tilt spool (Unused)

8.

Main relief valve

10-72

WF550-3 / WF550T-3


Main control valve

WF550-3

PA1.

From PPC valve P4

A1. To bucket cylinder bottom end

PA2.

From PPC valve P2

A2. To boom cylinder bottom end

PB1. From PPC valve P1

B1. To bucket cylinder head end

PB2. From PPC valve P3

B2. To boom cylinder head end

P.

From pump

D1. Drain port

P1.

From PPC valve P2

D2. Drain port

P2.

From PPC valve P3

T.

WF550-3 / WF550T-3

Drain port 10-73

Main control valve


1.

Main relief valve

6. Body

2.

Bucket spool return spring

7. Suction valve

3.

Boom spool return spring

8. Unloader valve

4.

Boom spool

9. Safety valve (with suction)

5.

Bucket spool

10-74

10. Float selector valve

WF550-3 / WF550T-3


Main relief valve

Main relief valve WF550T-3 1.

Main valve

2.

Valve seat

3.

Pilot seat

4.

Spring

5.

Adjustment screw

Function The relief valve is installed to the inlet portion of the main control valve. If the oil goes above the set pressure, the relief valve drains the oil to the tank to set the maximum pressure for the work equipment circuit, and to protect the circuit.

Operation •

Port A is connected to the pump circuit and port C is connected to the drain circuit. The oil passes through the orifice in main valve (1), and fills port B. Pilot poppet (3) is seated in valve seat (2).

•

If the pressure inside ports A and B reaches the set pressure of pilot poppet spring (4), pilot poppet (3) opens and the oil pressure at port B escapes from port D to port C, so the pressure at port B drops.

•

When the pressure at port B drops, a difference in pressure between ports A and B id created by the orifice of main valve (1). The main valve is pushed open and the oil at port A passes through port C, and the abnormal pressure is released to the drain circuit.

•

The set pressure can be changed by adjusting the tension of pilot poppet spring (4). To change the set pressure, remove the cap nut, loosen the locknut, then turn adjustment screw (5) to adjust the set pressure as follows. TIGHTEN to INCREASE pressure LOOSEN to DECREASE pressure

WF550-3 / WF550T-3

10-75

Main relief valve


WF550-3 1

1.

Main valve

2.

Valve seat

3.

Pilot poppet

4.

Spring

5.

Adjustment screw

6.

Locknut

2

3

4

5

6

SEW00162

Set pressure: 20.6 MPa {210 kg/cm²}

Function The relief valve is installed to the inlet portion of the main control valve. If the oil goes above the set pressure, the relief valve drains the oil to the tank to set the maximum pressure for the work equipment circuit, and to protect the circuit.

A

1

B

2

3

Operation •

•

Port A is connected to the pump circuit and port C is connected to the drain circuit. The oil passes through the orifice in main valve (1), and fills port B. Pilot poppet (3) is seated in valve seat (2). If the pressure inside ports A and B reaches the set pressure of pilot poppet spring (4), pilot poppet (3) opens and the oil pressure at port B escapes from port D to port C, so the pressure at port B drops.

•

When the pressure at port B drops, a difference in pressure between ports A and B is created by the orifice of main valve (1). The main valve is pushed open and the oil at port A passes through port C, and the abnormal pressure is released to the drain circuit.

•

The set pressure can be changed by adjusting the tension of pilot poppet spring (4). To change the set pressure, remove the cap nut, loosen the locknut (6), then turn adjustment screw (5) to adjust the set pressure as follows.

C

A

B

D

C

SEW00163

3

SEW00164

TIGHTEN to INCREASE pressure LOOSEN to DECREASE pressure

10-76

WF550-3 / WF550T-3


Main relief valve

Safety valve (with suction) 1 1.

Suction valve

2.

Main valve

3.

Main valve spring

4.

Pilot piston

5.

Suction valve spring

6.

Valve body

2

3

4

5

Set pressure: 22.6 MPa {230 kg/cm²}

6

SEW00166

Function The safety valve is in the bucket cylinder circuit inside the main control valve. If any abnormal pressure is generated by any shock to the cylinder when the main control valve is at the neutral position, this valve relieves the abnormal pressure to prevent damage to the cylinder.

Operation as safety valve •

Port A is connected to the cylinder circuit and port B is connected to the drain circuit. The oil pressure at port A is sent to port D from the hole in pilot piston (4). It is also sent to port C by the orifice formed from main valve (2) and pilot piston (4).

•

Pilot piston (4) is secured to the safety valve, and the size of the cross-sectional surface (cross-sectional area) has the following relationship: d2 > d1 > d3 > d4.

A

B

C

2

d1 d3 d4

•

If abnormal pressure is created at port A, suction valve (1) is not actuated because of relationship d2 > d1, but relationship between port A and port C is d3 > d4, so main valve (2) receives oil pressure equivalent to the difference between the areas of d3 and d4.If the oil pressure reaches the force (set pressure) of main valve spring (3), main valve (2) is actuated, and the oil from port A flows to port B.

A

B 1

4

d2

2

D

SEW00167

3

D

SEW00168

WF550-3 / WF550T-3

10-77

Main relief valve


Operation as suction valve If any negative pressure is generated at port A, port D is connected with port A, so there is also negative pressure at port D. The tank pressure of port B is applied to port E, so the safety valve receives oil pressure a, which is equal to the difference in the area of d2 and d1 because of the tank pressure at port E. Therefore, oil pressure e moves the valve in the direction of opening, and oil pressure a acts to move suction valve (1) in the direction of closing. When the pressure at port A drops (and comes close to negative pressure), it becomes lower than hydraulic pressure e. The relationship becomes oil pressure e > oil pressure a + force of valve spring (5), and suction valve (1) opens to let the oil from port B flow into port A and prevent any negative pressure from forming at port A.

10-78

WF550-3 / WF550T-3


Suction valve

Suction valve 1 1.

Main poppet

2.

Sleeve

3.

Spring

2

3

SEW00170

Function This valve acts to prevent any negative pressure from forming in the circuit.

Operation If any negative pressure is generated at port A (boom cylinder rod end) (when a pressure lower than tank circuit port B is generated), main poppet (1) is opened because of the difference in area between d1 and d2, and oil flows from port B at the tank end to port A at the cylinder port end.

WF550-3 / WF550T-3

10-79

Float selector valve and unload valve


Float selector valve and unload valve WF550-3 Function The float selector valve and unload valve are inside the main control valve. When the boom lever is operated to the FLOAT position, the float selector valve detects this, and it is actuated to actuate the unload valve and set the boom to the FLOAT position.

From PPC valve

To PPC valve

Operation •

If the boom lever is pushed further from the LOWER position, it is set to the FLOAT position and the PPC valve is set to the same condition as for the LOWER position. The pressure at port A becomes high pressure and the pressure at port B becomes low pressure.

•

The oil from the steering valve fills chamber F and chamber E.

•

If the difference in pressure between port A and port B becomes greater than the specified pressure, float selector valve (2) is moved to the right, and port C and port D open.

•

When port C is opened, the oil pressure in chamber E drops, unload valve (4) is moved up in the direction of the arrow, and the oil from the pump flows to the drain circuit, and also flows to the rod end of the boom cylinder. The oil at the bottom end of the boom cylinder is connected to the drain circuit and forms the FLOAT position.

From steering valve

From PPC valve

To PPC valve

From steering valve

10-80

WF550-3 / WF550T-3


Float selector valve and unload valve


WF550-3 / WF550T-3

10-81

Operation (WF550T-3)



RAISE

HOLD

FLOAT LOWER

Lift spool hold position

From PPC pump To hydraulic tank

10-82

From pump

To hydraulic tank

To hydraulic tank

WF550-3 / WF550T-3


•

The oil enters port A from the pump, and the maximum pressure is set by relief valve (11).

•

Tilt spool (1) is at the HOLD position, so the bypass circuit is open and the oil at port A passes around the spool and flows to port B. Lift spool (2) is also at HOLD, so the bypass circuit is open and the oil at port B passes around the spool, enters port C of the drain circuit, passes through the filter, and returns to the tank.

•

The oil from the PPC pump passes through check valve (13), and enters port L of the PPC valve. However, work equipment lever are at the HOLD position, so the oil returns to the hydraulic tank from PCC relief valve (12).

WF550-3 / WF550T-3


10-83



RAISE

HOLD

LOWER

FLOAT

Lift spool at raise position

From accumulator charge valve

To hydraulic tank

10-84

From pump

To hydraulic tank

WF550-3 / WF550T-3


•

When work equipment lever (3) is pulled, the oil flows from port L of the PPC valve to port N and port T. In addition, the oil at port S passes through port M and flows to the drain circuit.

•

The oil pressure at port T pushes lift spool (2) and moves it to the RAISE position.

•

The oil from the pump passes through the bypass circuit of the tilt spool and flows to the bypass circuit of lift spool (2). The bypass circuit is closed by the spool, so the oil pushes open check valve (10). The oil flows from port J to port K, and flows to the cylinder rod.

•

At the same time, the oil at the cylinder bottom end enters drain port C from port I and returns to the tank. Therefore, the blade rises.

WF550-3 / WF550T-3


10-85



RAISE

HOLD

LOWER

FLOAT

Lift spool at lower position


To hydraulic tank

10-86

From pump

To hydraulic tank

WF550-3 / WF550T-3


•

When work equipment lever (3) is pushed, the oil flows from port L of the PPC valve to port M and port S. In addition, the oil at port T flows to the drain circuit.

•

The oil pressure at port S pushes lift spool (2) and moves it to the LOWER position.

•

The oil from the pump passes through the bypass circuit of the tilt spool and flows to the bypass circuit of lift spool (2). The bypass circuit is closed by the spool, so the oil pushes open check valve (10). The oil flows from port H to port I, and flows to the cylinder bottom end.

•

At the same time, the oil at the cylinder rod enters drain port C from port K and returns to the tank. Therefore, the blade goes down.

WF550-3 / WF550T-3


10-87



RAISE

HOLD

LOWER

FLOAT

Lift spool at float position


To hydraulic tank

10-88

From pump

To hydraulic tank

WF550-3 / WF550T-3


•

When work equipment lever (3) is pushed to the FLOAT position, the PPC valve spool moves beyond the LOWER position to the FLOAT position. The pressure oil at port L flows to port M, and at the same time, it also flows to port S. In addition, the pressurized oil at port T flows to port N.

•

The pressurized oil at port S pushes lift spool (2) to the FLOAT position.

•

Accordingly, the oil on the cylinder bottom side flow through port H to port C and the drain circuit, and the oil on the cylinder rod side flows through port K to port C and the drain circuit. As a result, the blade floated.

WF550-3 / WF550T-3


10-89

Operation (WF550-3)


Operation (WF550-3) Boom and bucket spool hold position HOLD

From PPC pump To hydraulic tank

10-90

From pump

To hydraulic tank

To hydraulic tank

WF550-3 / WF550T-3


•

The oil enters port A from the pump, and the maximum pressure is set by relief valve (11).

•

Bucket spool (1) is at the HOLD position, so the bypass circuit is open and the oil at port A passes around the spool and flows to port B. Boom spool (2) is also at HOLD, so the bypass circuit is open and the oil at port B passes around the spool, enters port C of the drain circuit, passes through the filter, and returns to the tank.

•

The oil from the PPC pump passes through check valve (13), and enters port L of the PPC valve. However, the boom and bucket levers are at the HOLD position, so the oil returns to the hydraulic tank from PCC relief valve (12).

WF550-3 / WF550T-3

Operation (WF550-3)

10-91

Operation (WF550-3)


Boom spool at raise position HOLD

RAISE

From PPC pump

To hydraulic tank

10-92

From pump

To hydraulic tank

WF550-3 / WF550T-3


•

When work equipment lever (3) is pulled, the oil flows from port L of the PPC valve to port N and port S. In addition, the oil at port T passes through port M and flows to the drain circuit.

•

The oil pressure at port S pushes boom spool (2) and moves it to the RAISE position.

•

The oil from the pump passes through the bypass circuit of the bucket spool and flows to the bypass circuit of boom spool (2). The bypass circuit is closed by the spool, so the oil pushes open check valve (10). The oil flows from port H to port I, and flows to the cylinder bottom.

•

At the same time, the oil at the cylinder rod end enters drain port C from port K and returns to the tank. Therefore, the boom rises.

WF550-3 / WF550T-3

Operation (WF550-3)

10-93

Operation (WF550-3)


Boom spool at lower position HOLD LOWER

From PPC pump

To hydraulic tank

10-94

From pump

To hydraulic tank

WF550-3 / WF550T-3


•

When work equipment lever (3) is pushed, the oil flows from port L of the PPC valve to port M and port T. In addition, the oil at port S flows to the drain circuit.

•

The oil pressure at port T pushes boom spool (2) and moves it to the LOWER position.

•

The oil from the pump passes through the bypass circuit of the bucket spool and flows to the bypass circuit of boom spool (2). The bypass circuit is closed by the spool, so the oil pushes open check valve (10). The oil flows from port J to port K, and flows to the cylinder rod end.

•

At the same time, the oil at the cylinder bottom enters drain port C from port I and returns to the tank. Therefore, the boom goes down.

WF550-3 / WF550T-3

Operation (WF550-3)

10-95

Operation (WF550-3)


Boom spool at float position HOLD FLOAT

From PPC pump

To hydraulic tank

10-96

From pump

To hydraulic tank

WF550-3 / WF550T-3


•

When work equipment lever (3) is pushed to FLOAT position, the PPC valve spool moves beyond the LOWER position to the FLOAT position. The pressure oil at port L flows to port M, at the same time, it also flows to port T and port W. In addition, the pressurized oil at port S flows to port N.

•

The pressurized oil at port T pushes boom spool (2) to the LOWER position.

•

If a difference in pressure greater than the specified pressure is generated at port W and port X, valve (7) moves to the right, opens port C 1 and port C, and connects to the drain circuit. When port C 1 is connected to the drain circuit, unload valve (8) moves up and the oil from the pump flows to the drain circuit.

•

Therefore, the oil at the cylinder rod end passes from port K through unload valve (8) and flows to the drain circuit. The oil at the cylinder bottom flows from port I to port C, and then flows to the drain circuit. Therefore, the boom is set to the FLOAT condition.

WF550-3 / WF550T-3

Operation (WF550-3)

10-97

Operation (WF550-3)


Bucket spool at dump position DUMP

HOLD

From PPC pump

To hydraulic tank

10-98

From pump

To hydraulic tank

WF550-3 / WF550T-3


•

When work equipment lever (3) is tilted to the right, the pressure oil at port L of the PPC valve flows from port Q to port V. In addition, the oil at port R flows to the drain circuit. The pressure oil at port V moves bucket spool (1) to the DUMP position.

•

The bypass circuit is closed by bucket spool (1), so the oil from port A pushes open check valve (9). The oil from check valve (9) flows from port F to port G, and then flows to the cylinder rod end.

•

At the same time, the oil at the cylinder bottom flows from port D to drain port C, and returns to the tank, so the bucket is dumped.

WF550-3 / WF550T-3

Operation (WF550-3)

10-99

Operation (WF550-3)


Bucket spool at tilt position HOLD

TILT

From PPC pump

To hydraulic tank

10-100

From pump

To hydraulic tank

WF550-3 / WF550T-3


•

When work equipment lever (3) is tilted to the left, the pressure oil at port L of the PPC valve flows from port P to port R. In addition, the oil at port V flows to the drain circuit. The pressure oil at port R moves bucket spool (1) to the TILT position.

•

The bypass circuit is closed by bucket spool (1), so the oil from port A pushes open check valve (9). The oil from check valve (9) flows from port D to port E, and then flows to the cylinder bottom.

•

At the same time, the oil at the cylinder rod end flows from port G to drain port C, and returns to the tank, so the bucket is tilted.

WF550-3 / WF550T-3

Operation (WF550-3)

10-101

Bucket positioner and boom kick-out (WF550-3)


Bucket positioner and boom kick-out (WF550-3) Operation of proximity switch for boom kick-out Boom RAISE •

When the boom is lower than the set position for the kickout, the detector (steel plate) is not above the detection surface of the proximity switch, so the proximity switch load circuit is shut off.

Proximity switch for boom kick-out

The relay switch is turned OFF and the current for the solenoid is shut off.

To battery relay

Kick-out relay Kick-out solenoid

Boom lever Cam

Proximity switch

Boom Roller

Detector

PPC valve

10-102

WF550-3 / WF550T-3


•


When the work equipment (boom) lever is moved to the RAISE position, the boom spool is held at the RAISE position by the cam follower and cam on the lever, and the boom rises.

Proximity switch for boom kick-out To battery relay


Boom lever Boom

Proximity switch

Cam

Roller

Detector

WF550-3 / WF550T-3

10-103


•


When the boom rises and reaches the set position for the kick-out, in other words, the detector (steel plate) is in position on the detection surface of the proximity switch, an electric current is sent to the solenoid by the action of the proximity switch and relay circuit. As a result, the solenoid is actuated, and the cam is pulled away from the cam detent, so the boom spool is returned to the HOLD position by the return spring.

Proximity switch for boom kick-out

To battery relay


Boom lever Proximity switch Cam Boom

Roller

Detector

PPC valve

Action of proximity switch for boom-kickout

Position

When detector is in position at detection surface of proximity switch

When detector is separated from detection surface of proximity switch

Proximity switch actuation display

Lights up

Goes out

Proximity switch load circuit (relay switch circuit)

Current flows

Current is shut off

Relay switch load circuit (solenoid circuit)

Current flows

Current is shut off

10-104

WF550-3 / WF550T-3



Operation of proximity switch for bucket positioner Bucket TILT •

When the bucket is dumped beyond the set position for the auto-leveler, the sensor (steel plate) is above the detection surface of the bucket proximity switch, so electric current flows in the proximity switch load circuit. The positioner relay is turned ON and the current for the solenoid is shut off.

Proximity switch for bucket positioner

To battery relay

Positioner relay Positioner solenoid

Cam

Roller

Proximity switch

•

When the work equipment (bucket) lever is moved to the TILT position, the bucket spool is held at the TILT position by the cam follower and cam on the lever, and the bucket tilts.

Detector


To battery relay


Cam

Roller

Proximity switch

WF550-3 / WF550T-3

Detector

10-105


•

When the bucket tilts and reaches the set position for the bucket leveler, in other words, the sensor (steel plate) separates from the detection surface of the proximity switch, electric current is sent to the solenoid by the action of the proximity switch and relay circuit. As a result, the solenoid is actuated, and the cam is pulled away from the cam detent, so the bucket spool is returned to the HOLD position by the return spring.



To battery relay


Cam

Roller

Proximity switch

Detector

Action of proximity switch for bucket positioner

Position

When detector is in position at detection surface of proximity switch

When detector is separated from detection surface of proximity switch

Proximity switch actuation display

Lights up

Goes out

Proximity switch load circuit (relay switch circuit)

Current flows

Current is shut off

Relay switch load circuit (solenoid circuit)

Current is shut off

Current flows

10-106

WF550-3 / WF550T-3


Air conditioner

Air conditioner Air conditioner piping

1.

Vent

6. Air conditioner condenser

2.

Window defroster

7. Hot water inlet port

3.

Vent

8. Hot water outlet port

4.

Dry receiver

9. Air conditioner unit

5.

Comperssor

WF550-3 / WF550T-3

10. Controller

10-107

Machine monitor system



Alternator terminal R Starting motor terminal C Battery Dimmer switch Relays Buzzer

CHECK lamps CAUTION lamps Flashing synchronous signal

Main monitor

Maintenance monitor

Transmission controller Parking

Neutral

Travel speed (engine speed)

Network wiring Speed lange signal F. N. R signal Hold signal

10-108

Sensors

WF550-3 / WF550T-3



Outline •

The machine monitor system uses the sensors and other devices installed to various parts of the machine to observe the condition of the machine. It processes this information swiftly and displays it on the monitor panel to inform the operator of the condition of the machine.

•

The machine monitor system consists of the main monitor, maintenance monitor, sensors, switches, relays, alarm buzzer, and power source.

•

The displays can be broadly divided into the following: Cautions displayed on the monitors (abnormalities in the machine where an alarm is given) and normal conditions which are always displayed on the instrument panel (pilot lamps and readings for the gauges, speedometer, and service meter).

•

There are also various switches built into the monitor panel which function to operate the machine.

➀ ➁ ➂

The main monitor uses the network wiring to send signals to the controller, and functions to display the following information. Shift indicator: 1st - 4th, N, F, R (F, R are optional) HOLD Failure action code, failure code, time elapsed since failure (failure data display mode)

WF550-3 / WF550T-3

10-109

Main monitor


Main monitor

1.

Check lamp

4.

Switches

2.

Caution lamp

4A. Working lamp (front) switch

3.

Pilot items

4B. Working lamp (rear) switch

3A. Turn signal (left)

4C. Transmission cut-off switch

3B. Turn signal (right)

4D. Auto shift, manual selector switch

3C. Shift indicator 3D. Speedometer 3E. Parking brake 3F. Preheating 3G. Failure action code

10-110

WF550-3 / WF550T-3


Main monitor

Outline •

The main motor has a display function for the speedometer and other gauges and a switching function to control the electric components and controllers.

•

There is one CPU (Central Processing Unit) installed internally, and this processes the signals from the sensors and outputs the display.

•

A liquid crystal display and LEDs are used for the display. The switches are embossed sheet switches.

WF550-3 / WF550T-3

10-111

Main monitor


Main monitor display function Display category

Symbol

Display item

Display range

Display method

When there is abnormality display on maintenance monitor

Display flashes (for details, see MAINTENANCE MONITOR DISPLAY FUNCTION)

Parking brake actuated, transmission not at neutral

Display flashes and buzzer sounds

When there is abnormality display on maintenance monitor

Display flashes (buzzer may also sound) (for details, see MAINTENANCE MONITOR DISPLAY FUNCTION)

Hi beam (WF550-3 only)

When operated

Display lights up

Turn signal (left, right)

When operated

Display lights up

Parking brake

When operated

Display lights up Buzzer sounds when parking brake is applied and shift lever is not at N

Preheating

When preheating

Lights up Lighting up time changes according to engine water temperature when starting switch is turned ON (for details, see PREHEATING OUTPUT FUNCTION)

Shift hold

When shift is held

Display lights up

Speedometer

Travel speed

0 – 99 km/h

Digital display (display switches between tachometer and speedometer)

Shift indicator

Shift indicator

1–4N

Digital display

Check

Caution

Check

Caution

Pilot

Failure action code

10-112

Failure action code

When controller detects failure and action by operator is needed, CALL is displayed, or CALL AND E (action code) are displayed in turn

Digital display Buzzer sounds (For details of the travel data display mode, see TROUBLE DATA DISPLAY MODE)

WF550-3 / WF550T-3


Main monitor

Main monitor switch function Item

Function

Display

Actuation

Working lamp (front)

Front working lamp lights up or goes out each time switch is pressed when side lamps are lighted up

Lights up

Front working lamp lights up

Goes out

Front working lamp goes out

Working lamp (rear)

Rear working lamp lights up or goes out each time switch is pressed when side lamps are lighted up

Lights up

Rear working lamp lights up

Goes out

Rear working lamp goes out

Transmission cutoff

Transmission cut-off function is actuated or stopped each time switch is pressed

Lights up

Cut-off function actuated

Goes out

Cut-off function stopped

Auto shift mode switches to manual mode when switch is pressed

Lights up

Manual mode

Manual

Goes out

Auto shift mode

Preheating output function Item Electrical intake air heater

Operation ON Power source OFF ON Display OFF ON Output OFF

Display time: T(sec) Output time: T(sec)

Engine water temperature (°C)

WF550-3 / WF550T-3

10-113

Main monitor


Trouble data display mode (when optional controller are installed) Item Method of switching to trouble data display mode

Switch operation

Actuation

With engine stopped and starting switch turned ON, press 2nd switch from top on left side of main monitor (switch below emergency steering display) and working lamp (front) switch simultaneously for at least 5 seconds.

All switch displays (LEDs) go out, and failure code is displayed on speedometer display and time elapsed since failure is displayed on failure action code display.

ON

SDW00241

Method of sending failure code

Press working lamp (front) switch

1. Failure code is a two-digit display given in numbers or letters. The display for the failure now occurring flashes and the display for past failures lights up. If there is no failure, CC is displayed (000 is displayed for time elapsed since failure) 2. The time elapsed since failure is displayed as a three-digit number to show how long ago the failure occurred (the oldest failure time is displayed. Any time greater than 999H is displayed as 999H). 3. A maximum of 9 items are stored in memory for the failure code.

Failure code and time elapsed since failure change to next item. Failure code

ON

Time elapsed since failure

SDW00242

Clearing failure code

Press working lamp (rear) switch for at least 2 seconds

Failure code and time elapsed since failure being displayed are cleared. Failure code for problem now occurring (flashing display) cannot be cleared.

ON

SDW00243

Resetting from travel data display mode

10-114

Press 2nd switch from top on left side of main monitor (switch below emergency steering display) and working lamp (front) switch simultaneously for at least 5 seconds, or start the engine.

Changes to normal display

WF550-3 / WF550T-3


Main monitor


WF550-3 / WF550T-3

10-115

Maintenance monitor


Maintenance monitor

1.

2.

Check items (Checks before starting)

3.

Gauge items

1A. Engine water level

3A. Fuel level

1B. Engine oil level

3B. Engine water temperature

Caution items (warning items)

3C. Torque converter oil temperature

2A. Engine oil pressure

4.

Service meter

2B. Battery charge

4A. Service meter numeric display

2C. Brake oil pressure

4B. Service meter RUN pilot lamp

2D. Air cleaner

10-116

5.

Monitor module

6.

Switch module

WF550-3 / WF550T-3


Maintenance monitor

Outline •

The maintenance monitor has a display function for the caution items and gauges, and switch functions to control the work equipment controller.

•

The maintenance monitor consists of the monitor module, switch module, service meter, case, and other mechanisms.

•

The monitor module has a built-in CPU (Central Processing Unit). It processes the signal from the sensors, and carries out the display and output.

•

A liquid crystal display and LEDs are used for the display portions. The switches are embossed sheet switches.

WF550-3 / WF550T-3

10-117

Maintenance monitor


Maintenance monitor display function Display category

Symbol

Display item

Display range

Engine water level

Below low level

Engine oil level

Below low level

Engine water level

Below low level

Check

Caution

10-118

Displays when engine is stopped and starting switch is ON Display when normal: OFF Display when abnormal: Flashes CHECK lamp flashes

Displays when engine is running Display when normal: OFF Display when abnormal: Flashes CAUTION lamp flashes Buzzer sounds

Engine oil pressure

Below specified pressure

Brake oil pressure

Below specified pressure

Engine water temperature

Above 102°C

Buzzer sounds if above 105°C

Torque converter oil temperature

Above 120°C

Buzzer sounds if above 130°C

Fuel level

Below low level

Displays when engine is running Display when normal: OFF Display when abnormal: Flashes CAUTION lamp flashes

Battery charge

When charge is defective

Air cleaner

Above specified negative pressure

Service meter

0 – 9999.9h

Service meter

Gauges

Display method

Displays when engine is running Display when normal: OFF Display when abnormal: Flashes CHECK lamp flashes Actuated when charge is normal Advances 1 for every hour

Service meter indicator

Lights up when service meter is running

Fuel level

All lamps light up below applicable level Flashes when level is 1

Engine water temperature

One place lights up to show applicable level Flashes when level is 6 or 7

Torque converter oil temperature

One place lights up to show applicable level Flashes when level is 6 or 7

WF550-3 / WF550T-3


Maintenance monitor

All-Range Electronic Control Automatic Transmission System Outline of system

Auto shift All-range ECMV control Hold function Kickdown function Safety function Manual shift Kickdown function Engine selection function (Komatsu/Cummins) Part of joystick steering control function (option) Self-diagnostic function Condition display (output, failure code) Troubleshooting (detection of system abnormality, system disconnection, short circuit) Communications function

•

The all-range electronic control automatic transmission system consists of the transmission controller, directional and speed levers, engine speed sensor, speed sensor and allspeed-range ECMV (transmission clutch modulation valve).

•

The transmission controller controls the shifting to the appropriate speed range according to the lever position and travel speed signal.

•

To reduce shock when shifting gear (engaging the clutch), all-speed-range ECMV carries out modulation control.

•

To improve durability, there is a safety function which prevents the machine from moving suddenly when the engine is started, and a transmission protection function which protects the clutch when the direction of travel is changed.

•

The self-diagnostic function always observes the input and output condition, and displays the output condition on the two 7-segment LED displays on the transmission controller. There is also a failure detection function, and if any abnormality occurs, it displays a failure code. Depending on the condition, it also displays a failure action code on the main monitor and flashes the caution lamp to improve safety.

•

The transmission controller has a communications function, and it sends the speed range (N, 1st - 4th) data to the main monitor, which displays the speed range.

WF550-3 / WF550T-3

10-119

Maintenance monitor


System structure diagram

Range switch Transmission cut-off switch KDS (kickdown switch) Hold switch Engine speed Travel speed Neutralizer relay signal Engine speed

Failure code Transmission F, N, R switch Backup lamp relay

D

A

D

A

D

A

D

A

D

A

P

A

P

A

D

LED D D

S S S S

D

Fill switch (F, R, 1, 2, 3, 4) Transmission oil temperature Engine select

A: D: P: S:

R solenoid 1st solenoid 2nd solenoid 3rd solenoid 4th solenoid Kickdown signal

S

S

Manual switch

F solenoid

D Transmission controller

Direction switch

D

D

D

D

Shift indicator Hold pilot lamp Abnormality display buzzer output Main monitor F, N, R Tire compensation Model selection Damper function selection F1 (cut -off) output N output

A D

Analog signal Digital signal Pulse signal S-NET signal

10-120

WF550-3 / WF550T-3


Maintenance monitor

Function 1. Auto-shift function Shifting the transmission up or down is carried out when the engine speed is above 1450 rpm. Shifting is decided by signals from the directional lever, speed lever, and travel speed sensor according to [Table 1 Automatic gear shift change point table] recorded in the memory of the transmission controller. a. Speed lever (1st - 4th) This controls the maximum speed range (available speed range) for automatic gear shifting. Example: Speed lever at 4th: 2nd ñ 4th Speed lever at 2nd: 2nd only b. Directional lever N position To prevent the vehicle from moving accidentally, when the lever is at the neutral position, only the 2nd clutch is engaged. c.

Directional lever F position When the directional lever is operated from N to F, the transmission turns ON the F and 2nd ECMVs (F2). (Automatic start in 2nd) I.

Shift up (when speed lever is at 4th) When the accelerator pedal is depressed to increase the engine speed and the travel speed rises, when the travel speed reaches approx. 9.3 km/h, the ECMV 3rd is turned ON, and at the same time, 2nd is turned OFF. (Shifting to F3) When the travel speed rises further to approx. 17.6 km/h, the ECMV 4th is turned ON and at the same time, 3rd is turned OFF. (Shift to F4)

II. Shift down (speed lever at 4th) When traveling in 4th, if the accelerator pedal is let back, and the travel speed comes down to approx. 15.6 km/h, the ECMV 3rd is turned ON and 4th is turned OFF. (Shift to F3) When the travel speed goes down to approx. 9.8 km/h, the ECMV 2nd is turned ON and 3rd is turned OFF. (Switches to F2) d. Directional lever R position Automatic gear shifting is carried out according to the travel speed between 2nd and 4th speeds (when the speed lever is at 4th) in the same way as when the speed lever is at the F position. e. Skip shift When coasting (in engine speed OFF mode) in 3rd or 4th speed with the accelerator pedal depressed, if the travel speed is less than 8 km/h, the gear shifts down to 2nd to make it easier to accelerate. If the travel speed is more than 8 km/h, the speed range is maintained, and when the engine speed goes above 1450 rpm, the gear is shifted to a range that matches the travel speed. WF550-3 / WF550T-3

10-121

Maintenance monitor

f.


Gear shift prevention interval To prevent shift hunting after shifting gear, a time interval is set to maintain the speed range. The gear shift prevention interval differs according to the shift pattern. For details, see [Table 1 Automatic gear shift change point table].

2. Modulation control The modulation control acts to reduce the shock when shifting gear (when engaging the clutch). It uses the data for the engine speed, transmission oil temperature, and gear shift pattern to control the clutch oil pressure (including the characteristics when starting) to match the condition of the hydraulic circuit to control all speed ranges to the optimum according to the data in the transmission modulation table stored in the transmission controller memory. In addition, to reduce the torque cut, it carries out modulation control of the ECMV at the side which is switched OFF also. The transmission modulation data table is set for each transmission oil temperature. In addition, it has a learning function (transmission clutch piston data) to prevent any abnormal time lag when shifting gear. 3. HOLD function When the HOLD switch is pressed, the speed range is held at the optimum speed range, and even if the travel speed goes down, the transmission does not shift down. However, when switching between forward and reverse, the transmission normally shifts down to 2nd according to the travel speed, and then shifts up to the HOLD shift range according to the travel speed and gear shifting conditions. (This prevents any unnecessary shift down when leveling ground or when traveling downhill.) 4. Kickdown function When the operator turns the kickdown switch ON, it overrides the auto shift and switches down forcibly to 1st if the conditions (speed range, travel speed) in [Table 1 Automatic gear shift change point table, 5. Kickdown] are fulfilled. In addition, the transmission controller outputs the cut-off signal to the electronic governor controller during kickdown (1st output). The conditions for canceling this are if the travel speed rises or if the direction is shifted between forward and reverse. In these conditions, the gear is shifted to 2nd. This function is also effective when holding the speed range (hold, engine speed OFF mode).

10-122

WF550-3 / WF550T-3


Maintenance monitor

5. Travel mode Manual mode It is possible to switch between auto and manual shift. When using the manual mode, the gear is shifted according to the operation of the speed lever. When traveling in F2, it is also possible to use the kickdown function. 6. Safety function a. Neutral safety When the engine is started, if the directional lever is at any position other than N, the transmission controller keeps the transmission in neutral and prevents the machine from moving. If the N signal is input after the engine is started, the neutral safety is canceled. b. Speed lever priority It is possible to shift down immediately by operating the speed lever, so the engine can be used as a brake when traveling downhill. c.

Transmission protection When traveling in 3rd or 4th speed, the travel speed is controlled and a warning buzzer sounds to protect the transmission when shifting between forward and reverse. I.

Speed range control When the speed range control and travel speed fulfill the conditions for range I, the transmission shifts down to 2nd. When the speed range control and travel speed fulfill the conditions for range II, the speed range is maintained and the transmission shifts down to 2nd according to the deceleration. (For details, see Fig. 1 F-R selection gear shift pattern, Table 1 Automatic gear shift change point table, 7. F-R selection.)

II. Alarm buzzer When the speed range control and travel speed fulfill the conditions for range III, the alarm buzzer sounds to warn the operator. (If the engine speed is above 1700 rpm and the travel speed is above 13 km/h, or the travel speed is above 14 km/h) (See Fig. 2 F-R selection alarm buzzer range). d. Manual shift If the travel speed sensor is abnormal and it is impossible to detect the travel speed data, the transmission is set to manual (shift) mode.

WF550-3 / WF550T-3

10-123

Maintenance monitor


Table 1: Automatic gear shift change point table Speed range

Travel speed (km/h)

Gear shift prevention interval

1→2

5.1 (5.3) or above

2

2→3

8.7 (9.2) or above

2

3→4

15 or above

1

4→3

Less than 14.5

1

3→2

Less than 9.2 (8.7)

2

4→2

Less than 1.0

0

3→2

Less than 1.0

0

3. Engine speed (less than 1450 rpm → more than 1450 rpm)

4→2

Less than 8.0

2

3→2

Less than 8.0

2

4. Shift up when HOLD is ON

1→2

5.1

0

2→3

8.7

0

3→4

16.5

0

2→1

Whole range

5

3→1

Less than 12.0

5

4→1

Less than 12.0

5

6. FR selection (range I) (F → ) N → R (R → ) N → F

4→2 3→2 1→2

Note 1)

2

7. FR selection (range II) (F → ) N → R (R → ) N → F

→4 →3

Note 2) 16.5 or above Less than 14.5 – 16.5

2

8. FR selection F→N→F R→N→R

→4 →3 →2

6.5 or above Less than 8.7 – 16.5 Less than 8.7

0

Item 1. Basic shift change

2. Engine speed (less than 1450 rpm)

5. Shift down when kickdown is ON

NOTE 1 When the engine speed is less than 1900 rpm and the travel speed is less than 16 km/h, or the travelspeed is less than 13 km/h. NOTE 2 When the travel speed is 1900 rpm or above and the travel speed is 13 km/h or above, or the travel speed is 16 km/h or above, the speed range is maintained and the transmission shifts down to 2nd according to the deceleration.

Engine speed (rpm)

Engine speed (rpm)

Travel speed (km/h) Fig. 1: F-R selection gear shift pattern

10-124

Travel speed (km/h) Fig. 2: F-R selection alarm buzzer range

WF550-3 / WF550T-3


Maintenance monitor

7. Self-diagnostic function The transmission controller always observes the input and output signals of the automatic gear shifting system. It carries out self diagnosis and displays the results on the LEDs of the transmission controller. In addition, it sends the following data to the main monitor. a. Normal display: Transmission controller LEDs display output speed range. b. Failure code display: If an abnormality is detected, the nature of the failure is displayed as a code. For details of the failure code, see Table 2 Failure code table

Table 2: Failure code table System Code

Main monitor

Item Short circuit

Disconnection

Action code

10

Backup lamp relay

O

O

None

11

None

–

–

–

12

F ECMV Sol.

O

O

CALL

13

R ECMV Sol.

O

O

CALL

14

1st ECMV Sol.

O

O

CALL

15

2nd ECMV Sol.

O

O

CALL

16

3rd ECMV Sol.

O

O

CALL

17

4th ECMV Sol.

O

O

CALL

18

None

–

–

–

19

Joystick direction switch

O

O

E00

20

Direction switch signal

O

O

CALL

21

Range switch signal

O

O

None

22

Travel speed sensor

×

O

E00

23

Engine speed sensor

O

O

E00

24

Abnormality in memory (EEPROM)

–

–

None

25

Transmission oil temperature sensor

O

×

E01

26

F ECMV fill switch

O

×

CALL

27

R ECMV fill switch

O

×

CALL

28

1st ECMV fill switch

O

×

CALL

29

2nd ECMV fill switch

O

×

CALL

30

3rd ECMV fill switch

O

×

CALL

31

4th ECMV fill switch

O

×

CALL

32

F or R ECMV fill switch

×

O

E00

33

1st, 2nd, 3rd, or 4th ECMV fill switch

×

O

E00

WF550-3 / WF550T-3

10-125

Maintenance monitor


8. Communications function The transmission controller is equipped with a communications function using S-NET. It always maintains communications with the main monitor, and when the engine is started, it receives model, travel damper availability, and tire compensation data. When any abnormality occurs, it displays an action code on the main monitor according to the condition of the problem to warn the operator in order to increase safety. The failure code can recognize the codes recorded in the main monitor memory using the main monitor problem history mode. For details of operating the main monitor, see the section on the main monitor.

Transmission controller power source •

When the starting switch is turned ON and the supply voltage is more than 20V, and +20V or more is supplied to the transmission controller solenoid power source input, it is possible to drive each solenoid valve.

•

If the supply voltage is less than 19V, all outputs are turned OFF and the solenoids cannot carry out control (travel is impossible).

10-126

WF550-3 / WF550T-3


Maintenance monitor

Input signals 1. Directional lever (F, N, R) signal This signal is a +24V/OPEN digital signal, and when it is normal, one of F, N, or R signals (+24V) is input. 2. Speed lever (1st - 4th) signal This signal is a +24V/OPEN digital signal and +24V is input for the signal for the lever position. 3. Kickdown switch This signal is a +24V/OPEN digital signal and +24V is input when the kickdown switch on the work equipment control lever is pressed. The switch operation is judged from the +24V starting signal from the OPEN condition at that point. 4. Forward switch This signal is a +24V/OPEN digital signal and +24V is input when the HOLD switch on the work equipment control lever is pressed. The switch operation is judged from the +24V starting signal from the OPEN condition at that point. 5. Neutralizer relay signal This signal is a +24V/OPEN digital signal and +24V is input when the parking brake switch is pressed. When signal is OPEN, the transmission controller maintains the neutral condition. 6. Transmission cut-off signal This signal is a GND/OPEN digital signal, and when the transmission cut-off switch is operated (using the left brake), it changes to GND. When it is actuated, the transmission controller changes to the neutral output condition, and when it is restored, it sets to a suitable speed range for the travel speed at that point. 7. Manual mode signal This signal is a GND/OPEN digital signal, and when the manual mode switch is ON, GND is input. 8. Fill switch (F, R, 1st - 4th signals) This signal is a GND/OPEN digital signal, and is installed to each ECMV. The switch is operated by oil pressure. When the ECMV is on, GND is input.

WF550-3 / WF550T-3

10-127

Maintenance monitor


9. Engine selection signal This signal is a GND/OPEN digital signal, and when the engine is started, the type of engine mounted is judged from this signal. (The speed conversion data is different) Table 3: Engine selection signal table Input signal

Engine

Speed conversion data

OPEN

Komatsu

6

GND

Cummins

118

10. Memory clear signal This signal is a GND/OPEN digital signal. It is normally OPEN. When clearing the memory, start the engine, then input OPEN → GND → OPEN signals. 11. Engine speed sensor signal This signal is a pulse signal, and it converts the pulses from the electromagnetic pickup sensor to rotation speed for control. When the engine speed is 1450 rpm or above, it is called the engine speed ON mode, and when the speed is less than 1450 rpm, it is called the engine speed OFF mode. •

Komatsu engine: Speed P (rpm) = Input frequency (Hz) × 60/6

•

Cummins engine: Speed P (rpm) = Input frequency (Hz) × 60/118

12. Travel speed sensor signal This signal is a pulse signal, and it converts the pulses from the electromagnetic pickup sensor to rotation speed for control. To convert to the travel speed, the tire compensation data (communications data from the main monitor) are added. In addition, the acceleration is also calculated to judge the travel speed for gear shifting. •

Speed P (rpm) = Input frequency (Hz) × 60/59

•

Travel speed V (km/h) = Speed P (rpm)/(101.6 × tire compensation value k) or Travel speed V (km/h) = Input frequency (Hz)/(99.9 × tire compensation value k)

13. Transmission oil temperature sensor signal This signal is an analog signal and converts 0 – 5 V inside the controller to temperature. This is used for selecting the modulation table when shifting gear.

10-128

WF550-3 / WF550T-3


Maintenance monitor

14. Communications signal (S-NET) This receives the following data set in the main monitor and is used for control. a. Model selection It selects the automatic gear shift change point data table for each model to use for shifting gear. b. Tire compensation data This adds the compensation value (covering a range from 0.86 to 1.14) to the speed data from the travel speed sensor to obtain an accurate travel speed.

WF550-3 / WF550T-3

10-129

Maintenance monitor


Output signals 1. Transmission modulation valve (ECMV command current) This signal is an electrical output (0 ñ 1A). There are six types of ECMV: R and F for direction, and 1st, 2nd, 3rd, and 4th for each speed range. This valve is a pressure control valve and converts to a pressure matching the value of the current flowing to the solenoid. Therefore, it controls the oil pressure for the clutch selected for each speed range and controls the engagement of each independent clutch. In addition, only the 2nd clutch is actuated when the transmission is at neutral. Table 4: Combination of speed ranges and ECMV ECMV F

R

1st

2nd

3rd

4th

Speed range F1

O

F2

O

F3

O

F4

O

O O O O

N R1

O

R2

O

R3

O

R4

O

O O O O

O : ON

2. Backup lamp relay signal This signal is a +24V digital (ON/OFF) output. It is actuated when the directional lever is placed at R and lights up the backup lamp and caution lamp. 3. F1 (cut-off) signal This signal is a +24V digital (ON/OFF) output. This signal is output when the kickdown is operated and sets the machine to F1. 4. Engine speed signal This outputs a signal at the same cycle as the engine speed sensor signal input to the transmission controller.

10-130

WF550-3 / WF550T-3


Maintenance monitor

5. Communications signal (main monitor display data) For details of the display position and operation of the main monitor, see the section on the main monitor. a. Speed range display 1st speed range output: 2nd speed range output: 3rd speed range output: 4th speed range output: Neutral:

[1] [2] [3] [4] [N]

b. HOLD display The pilot display is given on the main monitor when the HOLD function is ON.

WF550-3 / WF550T-3

10-131

Maintenance monitor


LED display When the engine is started, the display goes first to 1. "Program quality display mode", and next to 2. "Output speed range display mode". However, if any abnormality is detected, it goes immediately to the troubleshooting mode. 1. Program quality display mode When the power source is on, it switches once every second.

–° –°

7° 8°

2° 3°

1° 5°

A° 1°

0° 0°

→ To display mode 2

2. Output speed range display mode LED display X. Y. (Both dots are out) X:

Direction ECMV drive condition FORWARD [F]: F, REVERSE [R]: A, Neutral: 0

Y:

Speed range ECMV drive condition 1 - 4

Example

Display

Content

’0° 2°’

Neutral, 2nd

’F° 1°’

FORWARD, 1st

’A° 2°’

REVERSE, 2nd

’F° F°’

Neutral safety condition

0° 2° N

10-132

F° 2 °

→ To display mode 3 if failure is detected

Gear shift (F2 speed range displayed continuously)

WF550-3 / WF550T-3


Maintenance monitor

3. Troubleshooting display mode (currently existing failure) A cycle of [E-(2 sec)], [Code (2 sec)] is repeated. a. When there is one abnormal item Example

E° –°

2° 3°

→ Repeated

b. When there is two abnormal item Example

E° –°

WF550-3 / WF550T-3

2° 3°

E° –°

1° 8°

→ Repeated

10-133

Transmission controller



10-134

WF550-3 / WF550T-3



Connector signals CNC1

CNC3A

CNC4

1

Joystick N output

1

—

1

—

2

Buzzer signal

2

—

2

Engine speed

3

Relief sol.

3

—

3

—

4

Engine speed output

4

—

4

—

5

Low pressure sol.

5

—

5

—

6

GND

6

Pressure sensor power supply

6

—

7

Power supply (+24V)

(+24V)

7

—

8

F1 output

7

Potentio power supply

8

—

9

ECSS sol. 5

8

—

9

GND (for rotate sensor)

10

High pressure sol.

9

—

10

—

11

Back lamp relay

10

Engine select

11

—

12

GND

11

Transmission oil temp. sensor

12

—

13

Power supply (+24V)

12

—

13

—

14

—

15

—

16

GND (for pressure sensor)

17

GND (for potentio)

18

—

19

Joy stick ON/OFF switch

20

Pressure switch

CNC2

CNC3B 1

CNC5

1

Sol. power supply (+24V)

Pressure switch B

1

GND (for puls)

2

ECMV 3 (+)

2

Fill switch F

2

Speed

3

—

3

Fill switch 1

3

GND

4

ECMV 4 (+)

4

Network (-)

4

GND

5

—

5

Direction F

5

Kick down switch

6

—

6

Direction R

6

T/M cut off switch

7

ECMV F (+)

7

Range switch 1

7

Joy stick N (NC)

8

ECMV R (+)

8

Range switch 3

8

Joy stick F (NC)

9

ECMV 1 (+)

9

ECSS switch

9

Joy stick R (NC)

10

ECMV 2 (+)

10

Fill switch R

10

GND (for puls)

11

P GND

11

Fill switch 2

11

Fill switch 3

12

Sol. power supply (+24V)

12

Network (-)

12

Fill switch 4

13

ECMV 3 (-)

13

Direction N

13

Hold switch

14

—

14

Neutralizer relay

14

Manual switch

15

ECMV 4 (-)

15

Range switch 2

15

Joy stick N (NO)

16

—

16

Range switch 4

16

Joy stick F (NO)

17

ECMV F (-)

17

Joy stick R (NO)

18

ECMV R (-)

19

ECMV 1 (-)

20

ECMV 2 (-)

21

P GND

WF550-3 / WF550T-3

10-135



WF550-3 / WF550T-3



WF550-3 / WF550T-3

Electric transmission control



1.

Transmission cut-off selector switch

8. Fuse boxes

2.


9. Transmission controller

3.

Directional lever

10. Transmission control valve

4.

Speed lever

11. Speed sensor

5.

Kick-down switch (WF550-3 only)

12. Transmission cut-off switch

6.

Maintenance monitor

13. Brake valve (left)

7.

Relays

14. Brake valve (right)

10-140

WF550-3 / WF550T-3



Function 1

Selection of F, R, and N positions

Using directional lever

2

Selection of speed range

Using speed lever

3

Kick-down switch (WF550-3 only)

When traveling in F2, it is possible to shift down to 1st using this switch without using the speed lever. If directional lever is operated to R or N, speed range automatically returned to 2nd.

4

Transmission cut-off function

Transmission is shifted to neutral when left brake is operated

5

Transmission cut-off selector function

It is possible to select whether to actuate or not actuate the transmission cut-off function. In this way, it is possible to obtain the same or greater ease of operation as on conventional loaders with the left brake when carrying out scooping work or when loading or unloading the machine from a trailer.

6

Neutralizer

To prevent seizure of the parking brake when traveling with the parking brake applied, the transmission is shifted to neutral when the parking brake is applied.

7

Neutral safety function

If the directional lever is not at the N position, the engine will not start when the starting switch is turned. This prevents the machine from starting suddenly. (For details, see STARTING CIRCUIT.)

8

Warning function

When traveling in reverse, the backup lamp lights up and the backup horn sounds to warn people in the area.

WF550-3 / WF550T-3

10-141



Combination switch

2

7

8

1

3

9

10

4

6

5

SDW00301

Outline The directional lever has three positions and the speed lever switch has four positions. As an individual part, the switch does not have a detent mechanism; the detent mechanism is in the combination switch. Each switch is positioned by two pins, and is secured to the body by three screws. When each lever is operated to the desired position, the switch, which is interconnected by a shaft, acts to allow electric current to flow to that circuit only.

General locations, function 1

Directional lever switch

Switches between F, R, and N

2

Speed lever switch

Selects speed range

3

Speed lever stopper

Stopper used to prevent speed lever from entering 3rd or 4th during operations

4

Turn signal indicators

Direction indicator lamps used when turning left or right

5

Self cancel

Turn signal indicator lever automatically returns to central position after machines turns left or right

6

Lamp switch

Switches on clearance lamp, head lamp, parking lamp, etc.

7

Dimmer switch (WF550-3 only)

Selects high beam for travel and low beam for passing

8

Hazard switch

Makes both left and right turn signal indicator lamps flash at the same time

9

Emergency flashing pilot lamp

Flashes at the same time as the emergency flashing lamp flashes

10


Applies or releases parking brake

10-142

WF550-3 / WF550T-3



Operation •

Directional lever (1) and shaft (2) of the speed lever of the combination switch form one unit with magnet (3), and magnet (3) also moves together withlever (1).

•

Control switch (5) with built-in hole IC (4) is installed at the bottom of magnet (3), and hole IC (4) is positioned on the board to match each position.

•

When directional lever (1) is operated to the F position, magnet (3) is immediately above hole IC (4) for the F position of the control switch.

F

N R

2

1

The magnetism from magnet (3) passes through the gap and case (6), and magnetism is applied to hole IC (4). •

When this happens, hole IC (4) is inside a magnetism detection circuit, so it detects the magnetism of magnet (3) and sends the F position signal to the electric current amplification circuit. In the electric current amplification circuit, a signal is output to actuate the transmission.

WF550-3 / WF550T-3

3 4

6

5 SEW00302

10-143



WF550-3 / WF550T-3



WF550-3 / WF550T-3




10-146

WF550-3 / WF550T-3

20 TESTING AND ADJUSTING Standard value table for engine . . . . . . . . . . 20-3 Standard value table for chassis . . . . . . . . . 20-4 WF550-3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20-4 WF550T-3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20-9 Standard value table for electrical parts . . 20-13 Table of required tools . . . . . . . . . . . . . . . 20-101 Sketch of special tools . . . . . . . . . . . . . . . 20-102 Tool N . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20-102 Measuring blow-by pressure . . . . . . . . . . 20-103 Measuring engine oil pressure . . . . . . . . . 20-104 Adjusting speed sensor . . . . . . . . . . . . . . 20-105 Engine speed sensor . . . . . . . . . . . . . . . . . . 20-105 Transmission output shaft speed sensor . . . 20-105 Adjusting of engine stop motor cable . . . 20-106 Torque converter and transmission oil pressure . . . . . . . . . . . . . . . . . . . . . . . . . 20-108 Steering oil pressure . . . . . . . . . . . . . . . . . 20-112 Measuring . . . . . . . . . . . . . . . . . . . . . . . . . . 20-112 Adjusting . . . . . . . . . . . . . . . . . . . . . . . . . . . 20-114 Measuring parking brake oil pressure . . . 20-115 Testing and adjusting PPC oil pressure . 20-117 Measuring . . . . . . . . . . . . . . . . . . . . . . . . . . 20-117 Adjusting . . . . . . . . . . . . . . . . . . . . . . . . . . . 20-119 Adjusting PPC valve linkage . . . . . . . . . . . 20-120 Work equipment hydraulic pressure . . . . 20-121 Adjusting . . . . . . . . . . . . . . . . . . . . . . . . . . . 20-122 Adjusting work equipment lever linkage . 20-123 Adjusting main monitor (speedometer module) . . . . . . . . . . . . . . . . 20-124 Troubleshooting Outline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20-202

Fan does not switch from forward to reverse rotation (selector switch position: AUTO) . . . . . . . . . .20-262 EC-4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20-263 Fan does not switch from forward to reverse rotation (selector switch position: MANUAL) . . . . . . .20-263 EC-5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20-264 Fan does not switch from reverse to forward rotation (selector switch position: AUTO) . . . . . . . . . .20-264 EC-6 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20-265 Fan does not switch from reverse to forward rotation (selector switch position: MANUAL) . . . . . . .20-265 EC-7 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20-266 When direction of fan is switched, it immediately switches . . . . . . . . . . . . . . . . .20-266

Troubleshooting of hydraulic and mechanical system (H Mode) H-1 Blade does not move . . . . . . . . . . . . . .20-302 H-2 Blade is slow or blade lacks power . . .20-303 H-3, H-4, H-5, H-6 . . . . . . . . . . . . . . . . . . . . .20-304 H-3 – When blade is raised, it moves slowly at a certain height . . . . . . . . . . . . . . . . . . . . .20-304 H-4 – Blade cannot be pushed with lift cylinder (blade floats) . . . . . . . . . . . . . . . .20-304 H-5 – Excessive hydraulic drift of blade . . . . .20-305 H-6 – Blade shakes during operation . . . . . .20-305 ★ The following precautions are necessary when using the Standard Value Tables to make judgements during troubleshooting or during testing and adjusting.

Connector types and mounting locations 20-203 Connector arrangement diagram . . . . . . . 20-206 Troubleshooting for radiator cooling fan System (EC Mode) Electric circuit diagram of cooling fan system . . . . . . . . . . . . . . . . . . . 20-252 EC-1 Fan does not rotate (selector switch position: AUTO) . . . . . . . 20-254 EC-2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20-258 Fan does not rotate (selector switch position: MANUAL) . . . . . . . 20-258 EC-3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20-262

WF550-3 / WF550T-3

1. The values in these tables are based on the values for new machines leaving the plant, so they should be used as target values when repairing or when estimating wear after a period of use. 2. The standard values in these tables for judgement when troubleshooting are estimated values based on the standard values for the machine when shipped from the plant. and on the results of various tests. Therefore, they should be used as reference in combination with repair and operating records when making judgements.

20-1

3. These standard value tables must not be used for standard values when judging claims. In addition, do not use these values alone to make simple judgements.

When carrying out testing, adjusting or troubleshooting, stop the machine on level ground, install the safety bar on the frame, lower the bucket to the ground, and stop the engine.

When installing or removing gauges, loosen the oil filler cap slowly to release the pressure inside the hydraulic tank. Then operate the control levers several times to release the remaining pressure in the hydraulic piping.

When taking measurements, do not allow unauthorized persons near the machine.

The oil in the circuit is hot, so be careful not to get burned.

20-2

WF550-3 / WF550T-3

TESTING AND ADJUSTING

Standard value table for engine

Standard value table for engine Machine model

WF550-3, WF550T-3

Engine Category

Item

Measurement conditions

S6D140E-2 Standard value for new machine

Service limit value

725 ± 50

725 ± 75

2,350 ± 50

2,350 ± 100

2,100

—

°C

Max. 650

700

kPa {mmHg}

Min. 85.3 {640}

68.0 {510}

Max. 6.0

8.0

Max. 1.5

3.0

0.43

—

0.80

—

Unit

Low idling Engine Speed

High idling

rpm

Rated speed Exhaust temperature

Entire speed range (ambient temperature: 20°C)

Air supply (boost pressure)

At rated output

Engine related

Exhaust gas color

At sudden acceleration At rated output

Bosch index

Valve clearance (normal temperature)

Intake valve

Compression pressure (SAE30 oil)

Oil temperature: 40 - 60°C (Engine speed: 160 - 200 rpm)

{kg/cm2}

Min. 3.8 {39}

Max. 2.7 {27}

Blow-by pressure (SAE30 oil)

(Water temp: Operating range) At rated output

kPa {mmH2O}

Max. 14.7 {150}

29.4 {300}

(Water temp: Operating range) At high idling

MPa

0.34 - 0.49

0.2

{kg/cm2}

{3.5 - 5.0}

{2.1}

Oil pressure (SAE30 oil)

Exhaust valve

At low idling (SAE30) At low idling (SAE10W)

Oil temperature

Entire speed range (inside oil pan)

Fuel injection timing

Before top dead center

Alternator belt tension

Deflection of one belt when pressed with finger force of approx. 98 N (approx. 10 kg}

Fan belt tension

When new

Deflection when pressed with finger When adjusting force of approx. 98 N (approx. 10 kg} tension

Air conditioner compressor belt tension

WF550-3 / WF550T-3

Deflection when pressed with finger force of approx. 58.8 N (approx. 6kg)

mm MPa

MPa

Min. 0.12

0.08

{kg/cm2}

{1.2}

{0.8}

MPa

Min. 0.1

0.07

{kg/cm2}

{1.0}

{0.7}

°C

90 - 110

120

° (degree)

16 ± 1

16 ± 1

mm

13 - 15

13 - 15

mm

13 - 15

13 - 15

mm

17 - 19

17 - 19

mm

10 - 15

10 - 15

20-3

Standard value table for chassis


Standard value table for chassis WF550-3 Machine model

Directional lever

Category

Item Operating effort

N - FORWARD, REVERSE

Travel

N - FORWARD, REVERSE


• Engine stopped • Measure at center of lever knob

WF550-3 Unit N {kg} mm

Speed lever

1st - 2nd Operating effort

Operating effort


Travel Steering wheel

5.9 +4.9 -2.94

Min. 16.7 {1.7}

+4.9 -2.94 {0.6 +0.5 -0.3 }

Min. 16.7 {1.7}

35 ± 10

35 ± 20

35 ± 10

35 ± 20

35 ± 10

35 ± 20

HOLD→RAISE

Max. 19.0 {1.9}

Max. 28.5 {2.85}

RAISE→HOLD

Max. 11.0 {1.1}

Max. 16.5 {1.65}

HOLD→LOWER

Max. 20.0 {2.0}

Max. 30.0 {3.0}

—

—

Max. 30.0 {3.0}

Max. 45.0 {4.0}

Max. 10.0 {1.0}

Max. 15.0 {1.5}

HOLD→DUMP

Max. 19.0 {1.9}

Max. 28.5 {2.85}

HOLD→TILT

Max. 19.0 {1.9}

Max. 28.5 {2.85}

TILT→HOLD

Max. 10.0 {1.0}

Max. 15.0 {1.5}

69 ± 15

69 ± 30

55 ± 15

55 ± 30

69 ± 15

69 ± 30

60 ± 15

60 ± 30

60 ± 15

60 ± 30


2nd - 3rd

HOLD→LOWER

mm

HOLD→FLOAT HOLD→DUMP

• Engine speed: Low idling • Hydraulic oil temperature: 45 - 55°C

{0.6 5.9

LOWER→HOLD

N {kg}

mm

HOLD→TILT

Play

• Engine stopped • Machine facing straight to front

mm

Max. 50

50 - 100

Operating effort

• Flat, horizontal, straight, dry paved road surface

N {kg}

12.3 ± 2.3 {1.25 ± 0.25}

Max. 19.6 {2.0}

Turning speed

• Engine speed: High idling • Left lock - right lock

Turns

3.6 ± 0.4

Max. 4.5

Max. 5.5

Max. 6.5

Max. 3.1

Max. 4.5

Low idling Operating time High idling

20-4

35 ± 20

Min. 16.7 {1.7}

HOLD→RAISE

Bucket

35 ± 10

+4.9 -2.94 +0.5 -0.3 }

• Engine speed: Low idling LOWER→FLOAT • Hydraulic oil temperature: 45 - 55°C FLOAT→HOLD

Boom

Max. 16.7 {1.7}

+0.5

{0.6 -0.3 }

5.9

N {kg}

2nd - 3rd

3rd - 4th

Bucket

+4.9

5.9 -2.94

+0.5 -0.3 }

1st - 2nd

Boom

Service limit value

{0.6

3rd - 4th

Travel

Standard value for new machine

• Engine started • Hydraulic oil temperature: 45-55°C • Left lock - right lock

sec.

WF550-3 / WF550T-3



Machine model Category

Item

Operating angle

Accelerator pedal

Operating effort Neutral (α1)

Neutral (α1)

Top surface of floor

• Engine speed: Low idling • Hydraulic oil temperature 45 - 55°C

Service limit value

N {kg}

71.05 ± 2.45 {7.25 ± 0.25}

Max. 97 {10}

48

—

32

—

mm

53

—

N {kg}

294 ± 29.4 {30 ± 3}

Max. 421.4 {43}

45

—

+1 0

—

5 ± 0.5

—

2,140 ± 100

2,140 ± 200

2,180 ± 100

2,180 ± 200

1,820 ± 200

1,820 ± 300

deg.

Max. (α2)

15

Play

mm

Torque converter stall Engine speed

Unit

deg.

Operating effort Operating angle


Max. (α2)

Stopper height (L)

Brake pedal


WF550-3 Standard value for new machine

Hydraulic stall Torque converter stall + Hydraulic stall

• Engine water temperature: Operating range • Torque converter oil temperature: 60-80°C • Hydraulic oil temperature: 45-55°C • Gearshift lever: F4 or R4

rpm

3.14

Low idling Main relief valve Transmission, torque converter

Rated speed Torque converter relief (inlet port) pressure

1st 2nd, 3rd, 4th, F•R

Lubrication pressure (oil cooler outlet port)

Steering

3.53 • Torque converter oil temperature: 60 - 80°C • Engine speed: High idling

Torque converter outlet port oil pressure ECMV output (clutch) oil pressure

Steering relief pressure

Orbit-roll output pressure

WF550-3 / WF550T-3

± 0.2

{32 ± 2}

MPa 2

{kg/cm } • Torque converter oil temperature: 60 - 80°C • Engine speed: High idling • Manual switch: ON • Torque converter oil temperature: 60 - 80°C • Engine speed: High idling

± 0.15

MPa {kg/cm2}

± 0.2

{32 ± 2} 3.53

± 0.15

{36 ± 1.5}

{36 ± 1.5}

1.18 ± 0.15

1.18 ± 0.15

{12 ± 1.5}

{12 ± 1.5}

0.39 ± 0.1

0.39 ± 0.1

{4 ± 1}

{4 ± 1}

3.38 ± 0.34

3.38 ± 0.34

{34.5 ± 3.5}

{34.5 ± 3.5}

3.48 ± 0.25

3.48 ± 0.25

{35.5 ± 2.5}

{35.5 ± 2.5}

0.21 ± 0.08

0.21 ± 0.08

{2.15 ± 0.85}

{2.15 ± 0.85}

+1.0

20.6 +1.0 -1.3

+10 -3 }

{210

20.6 -0.3 • Hydraulic oil temperature: 45 - 55°C • Engine speed: High idling

3.14

{210

+0.2 0 {38 +20 }

3.7

+10 -13 }

+0.4 -0.2 {38 +4 -2 }

3.7

20-5



Machine model

Accumulator

Category

Item

Charge cut-in pressure

Charge cut-out pressure

Measurement conditions • Engine speed: Low idling • Hydraulic oil temperature: 45-55°C

Power train

FORWARD

Travel speed

REVERSE

Brake oil pressure

WF550-3

Point where brake oil pressure warning lamp goes out Point where oil pressure is going up and then starts to go down

MPa {kg/cm2}

5.1 ± 0.3

5.1 ± 0.3

2nd

9.2 ± 0.5

9.2 ± 0.5

3rd

15.3 ± 0.8

15.3 ± 0.8

4th

20.0 ± 1.0

20.0 ± 1.0

Km/h

7.9 ± 0.4

7.9 ± 0.4

14.1 ± 0.7

14.1 ± 0.7

3rd

17.0 ± 0.9

17.0 ± 0.9

4th

27.4 ± 1.4

27.4 ± 1.4

± 0.49

4.9 ± 0.69

4.9

• Hydraulic oil temperature: 45-55°C

• Measure piston stroke

{50 ± 5}

{50 ± 7}

Max. 0.49 {5}

Max. 0.49 {5}

m

Max. 5

Max. 5

mm

3.9 ± 0.5

8.5

MPa {kg/cm2}

3.2

Low idling

Parking brake

20-6

9.8

2nd

Disc wear

± 0.15

{32.5 ± 1.5}

± 0.15

3.5 ± 0.15

{36 ± 1.5}

{36 ± 1.5}

{kg/cm2}

2.9 ± 0.3

2.9 ± 0.3

{30 ± 3}

{30 ± 3}

± 0.15

3.5 ± 0.15

{36 ± 1.5}

{36 ± 1.5}

—

Stopped

Stopped

mm

3.2 ± 1

2.77

3.5 • Flat paved road with 1/5 (11°20’) grade • Dry road surface • Machine at operating condition

3.2 ± 0.15 {32.5 ± 1.5}

MPa

3.5 • Torque converter oil temperature: 60 - 80°C • Engine at High idling

Parking brake pilot pressure

Disc thickness

9.8

1st

Performance

Performance

{60

+1.0 -0.5 +10 -5 }

1st

• Tire inflation pressure: Specified pressure • Flat, horizontal, straight, dry paved road surface • Speed when applying brake: 20 km/h, braking delay: 0.1 sec. • Brake pedal operating effort: Specified operating effort (294 ± 29.4 N {30 ± 3 kg}) • Measure braking distance

At emergency cancel

5.9

5.9

+1.5 -0.5 {100 +15 -5 }

• Engine stopped • Keep brake pedal depressed at 4.9 Mpa {50 kg/cm2} and measure drop in oil pressure after 5 min.

Parking Rated speed brake inlet port pressure

+0.5 0 {60 +50 }

Service limit value

+1.0 0 {100 +10 0 }

Drop in brake pressure Wheel brake

Unit


WF550-3 / WF550T-3




Item

PPC

PPC pump pressure PPC valve basic pressure (Orbit-roll basic pressure)

PPC valve output pressure

Boom RAISE, FLOAT; bucket DUMP, TILT Boom LOWER

Work equipment relief pressure

Blade RAISE

WF550-3


Unit


Service limit value

+0.98 0 +10 {100 0 }

+1,5 -0.5 +15 {100 -5 }

+0.2 0 +2 {38 0 }

3.7 ± 0.2

+0.2 0 +2 {38 0 }

3.7

9.8

• Hydraulic oil temperature: 45-55°C • Engine speed: High idling

3.7 MPa 2

{kg/cm } • Hydraulic oil temperature: 45-55°C • Engine speed: High idling • Control lever operated fully • Hydraulic oil temperature: 45-55°C • Engine speed: High idling

3.7

2.5 ± 0.05 {26 ± 0.5} MPa {kg/cm2}

• Hydraulic oil temperature: 45-55°C • Engine speed: High idling • No load

+1.0 -0.3 +10 {210 -3 }

9.8

{38 ± 2} +0.2 0 +2 {38 0 }

2.5 ± 0.05 {26 ± 0.5} +1.0 -1.3 +10 {210 -13 }

20.6

20.6

6.3 ± 0.3

Max. 7.0

3.5 ± 0.5

Max. 5.0

2.2 ± 0.3

Max. 3.0

1.6 ± 0.3

Max. 2.4

RAISE time sec.

• Hydraulic oil temperature: 45-55°C • Engine speed: High idling When fully operated Bucket tiltback

Work equipment speed

Work equipment

LOWER time Blade LOWER

When fully operated

sec. Horizontal Bucket horizontal (above ground)

WF550-3 / WF550T-3

20-7




Item

Hydraulic drift

Work equipment

Retraction of boom cylinder rod

Unit

• Hydraulic oil temperature: 45-55°C • Leave for 5 minutes after stopping engine then measure for next 15 minutes • Bucket empty, boom, bucket horizontal Work equipment posture

Retraction of bucket cylinder rod

20-8


WF550-3 Standard value for new machine

Service limit value

Max. 40

Max. 40

Max. 20

Max. 20

mm

WF550-3 / WF550T-3



WF550T-3 Machine model

Directionallever

Category

WF550T-3 Unit


Service limit value

N {kg}

+4.9 -2.9 {0.6 +0.5 -0.3 }

Max. 16.7 {1.7}

mm

35 ± 10

35 ± 20

+4.9 -2.9 {0.6 +0.5 -0.3 }

Min. 16.7{1.7}

+4.9 -2.9 {0.6 +0.5 -0.3 }

Min. 16.7{1.7}

+4.9 -2.9 +0.5 {0.6 -0.3 }

Min. 16.7{1.7}

35 ± 10

35 ± 20

35 ± 10

35 ± 20

35 ± 10

35 ± 20

Max. 23.5 {2.4}

Max. 35.3 {3.6}

Max. 23.5 {2.4}

Max. 35.3 {3.6}

Max. 24.5 {2.5}

Max. 37.3 {3.8}

—

—

LOWER→FLOAT

Max. 34.3 {3.5}

Max. 51.94 {5.3}

FLOAT→HOLD

Max. 23.5 {2.4}

Max. 35.3 {3.6}

67 ± 15

67 ± 30

53 ± 15

53 ± 30

67 ± 15

67 ± 30

Item Operating effort

NFORWARD, REVERSE

Travel

NFORWARD, REVERSE



5.9

Speed lever

1st - 2nd Operating effort

N {kg}

2nd - 3rd

3rd - 4th


2nd - 3rd

mm

3rd - 4th

Steering wheel

Operating effort

RAISE→HOLD Blade

HOLD→LOWER LOWER→HOLD

HOLD→RAISE

mm

Play

• Engine stopped • Machine facing straight to front

mm

Max. 50

50 - 100

Operating effort

• Flat, horizontal, straight, paved road surface

N {kg}

12.3 ± 2.5 {1.25 ± 0.25}

Max. 19.6 {2.0}

Turning speed

• Engine speed: High idling • Left lock - right lock

Turns

3.6 ± 0.4

Max. 4.5

Max. 5.5

Max. 6.5

Max. 3.1

Max. 4.5

Blade

HOLD→LOWER HOLD→FLOAT

Low idling Operating time High idling

Operating angle

Operating effort

Accelerator pedal

N {kg}


Travel


HOLD→RAISE


5.9

5.9

1st - 2nd Travel

5.9

Neutral (α1)

dry

• Engine started • Hydraulic oil temperature: 45-55°C • Left lock - right lock

sec.

• Engine speed: Low idling • Hydraulic oil temperature 45 - 55°C

N {kg}

71.05

± 2.45

{7.25 ± 0.25}

Max. 97 {10}

48

—

32

—

53

—

deg.

Max. (α2)

Top surface of floor Stopper height (L)

WF550-3 / WF550T-3

mm

20-9




Item

Operating angle

Brake pedal

Operating effort Neutral (α1)

WF550T-3

Measurement conditions • Engine speed: Low idling • Hydraulic oil temperature 45 - 55°C

N {kg}

mm

Hydraulic stall Torque converter stall + Hydraulic stall

• Engine water temperature: Operating range • Torque converter oil temperature: 60-80°C • Hydraulic oil temperature: 45-55°C • Gearshift lever: F4 or R4

Low idling

Rated speed Transmission, torque converter

Max. 421.4 {43}

45

—

+1 0

—

Torque converter relief (inlet port) pressure

2nd, 3rd, 4th, F•R

Steering

Steering relief pressure

Accumulator

Lubrication pressure (oil cooler outlet port)

Charge cut-in pressure

Orbit-roll output pressure

Charge cut-out pressure

—

2,140 ± 100

2,140 ± 200

2,180 ± 100

2,180 ± 200

1,820 ± 200

1,820 ± 300

3.14 ± 0.2

3.14 ± 0.2

{32 ± 2}

{32 ± 2}

3.53 • Torque converter oil temperature: 60 - 80°C • Engine speed: High idling

Torque converter outlet port oil pressure 1st

5 ± 0.5

rpm

Main relief valve

20-10

± 29.4

± 0.15

1.18 ± 0.15

1.18 ± 0.15

{12 ± 1.5}

{12 ± 1.5}

MPa

0.39 ± 0.1

0.39

{kg/cm2}

{4 ± 1}

Point where oil pressure is going up and then starts to go down

MPa (kg/cm2}

3.38 ± 0.34

3.38 ± 0.34

{34.5 ± 3.5}

{34.5 ± 3.5}

3.48 ± 0.25

3.48 ± 0.25

{35.5 ± 2.5}

{35.5 ± 2.5}

0.21 ± 0.08

0.21 ± 0.08

{2.15 ± 0.85}

{2.15 ± 0.85}

+1.0 -0.3 {210 +10 0 }

(kg/cm2}

20.6 +1.0 -1.3 {210

+0.2 -0.3 {38 +20 }

3.7

+0.5 0 {60 +50 }

5.9 {60

+1.0 0 {100 +10 0 }

9.8

+10 -13 }

+0.4 -0.2 {38 +4 -2 }

3.7

5.9 MPa

± 0.1

{4 ± 1}

20.6

Point where brake oil pressure warning lamp goes out

± 0.15

{36 ± 1.5}

• Torque converter oil temperature: 60 - 80°C • Engine speed: High idling

• Engine speed: Low idling • Hydraulic oil temperature: 45-55°C

3.53

{36 ± 1.5}

• Torque converter oil temperature: 60 - 80°C • Engine speed: High idling • Manual switch: ON

• Hydraulic oil temperature: 45 - 55°C • Engine speed: High idling

Service limit value

{30 ± 3}

15

Torque converter stall

ECMV output (clutch) oil pressure

294

deg.

Max. (α2)

Play

Engine speed

Unit


+1.0 -0.5 +10 -5 }

+1.5 -0.5 {100 +15 -5 }

9.8

WF550-3 / WF550T-3




Item

WF550T-3


Unit

1st

Power train

FORWARD

REVERSE

9.2 ± 0.5

9.2 ± 0.5 15.3 ± 0.8

± 1.0

20.0 ± 1.0

7.9 ± 0.4

7.9 ± 0.4

14.1 ± 0.7

14.1 ± 0.7

3rd

17.0 ± 0.9

17.0 ± 0.9

4th

27.4 ± 1.4

27.4 ± 1.4

4.9 ± 0.49

4.9 ± 0.69

{50 ± 5}

{50 ± 7}

Max. 0.49 {5}

Max. 0.49 {5}

m

Max. 5

Max. 5

mm

3.9 ± 0.5

8.5

Performance

• Tire inflation pressure: Specified pressure • Flat, horizontal, straight, dry paved road surface • Speed when applying brake: 20 km/h, braking delay: 0.1 sec. • Brake pedal operating effort: Specified operating effort (294 ± 29.4 N {30 ± 3 kg}) • Measure braking distance

Disc wear

• Measure piston stroke

MPa {kg/cm2}

Low idling

Parking brake

• Torque converter oil temperature: 60 - 80°C • Engine at High idling

• Flat paved road with 1/5 (11°20’) grade • Dry road surface • Machine at operating condition

Disc thickness

PPC

PPC valve basic pressure (Orbit-roll basic pressure) PPC valve output pressure

Blade raise, float, lower

WF550-3 / WF550T-3

• Hydraulic oil temperature: 45-55°C • Engine speed: High idling

3.2 ± 0.15 {32.5 ± 1.5}

3.5 ± 0.15

3.5 ± 0.15

{36 ± 1.5}

{36 ± 1.5}

{kg/cm2}

2.9 ± 0.3

2.9 ± 0.3

{30 ± 3}

{30 ± 3}

3.5 ± 0.15

3.5 ± 0.15

{36 ± 1.5}

{36 ± 1.5}

—

Stopped

Stopped

mm

3.2 ± 1

2.77

9.8

+0.98 0 {100 +10 0 }

+1.5 -0.5 {100 +15 -5 }

+0.2 0 {38 +20 }

3.7 ± 0.2

+0.2 0 {38 +20 }

3.7 ± 0.2

MPa {kg/cm2}

• Hydraulic oil temperature: 45-55°C • Engine speed: High idling • Control lever operated fully

3.2 ± 0.15 {32.5 ± 1.5}

MPa

Parking brake pilot pressure

PPC pump pressure

20.0

2nd

Drop in brake pressure

Wheel brake

Km/h

1st

• Engine stopped • Keep brake pedal depressed at 4.9 Mpa {50 kg/cm2} and measure drop in oil pressure after 5 min.

Performance

5.1 ± 0.3

15.3 ± 0.8

• Hydraulic oil temperature: 45-55°C

At emergency cancel

5.1 ± 0.3

3rd

Brake oil pressure

Parking brake inlet port Rated speed pressure

Service limit value

2nd

4th

Travel speed


3.7

3.7

9.8

{38 ± 2}

{38 ± 2}

20-11




Item

20-12

Work equipment speed

Work equipment

Work equipment relief pressure

Blade RAISE

Measurement conditions • Hydraulic oil temperature: 45-55°C • Engine speed: High idling

WF550T-3 Unit


MPa

20.6

{kg/cm2}

{210

• Hydraulic oil temperature: 45-55°C • Engine speed: High idling • No load

+1.0 -0.3 +10 -3 }

Service limit value 20.6 {210

+1.0 -1.3 +10 -13 }

1.7 ± 0.5

Max. 2.6

2.6 ± 0.5

Max. 5.0

RAISE time sec.

LOWER time Blade LOWER

WF550-3 / WF550T-3


Standard value table for electrical parts


Check carefully that there is no one in the surrounding area before starting inspection.

★ When carrying out operations during inspection, raise the work equipment control lever stand for operations, and lower it when traveling. ★ Turn the starting switch OFF before inserting the T-adapter or making any connections. Name of component

Power source

Connector no.

C1 C2

Inspection method

Measure voltage

System

Judgement table If the condition is as shown in the table below, it is normal

1. Turn starting switch OFF. 2. Insert T-adapter. 3. Turn starting switch ON.

Between C1 (7), (13) - chassis Between C2 (1), (12) - chassis Between C1 (7), (13) - (6),(12)


20 - 30 V

L01

ECMV Solenoid (1st)

CN4 (male)

ECMV Solenoid (2nd)

CN6 (male)

ECMV Solenoid (3rd)

CN12 (male)

ECMV Solenoid (4th)

CN8 (male)

ECMV Solenoid (F)

CN16 (male)

ECMV Solenoid (R)

CN14 (male)

WF550-3 / WF550T-3

Measure voltage


C3A

Measure Measure Measure Measure Measure Measure resistance resistance resistance resistance resistance resistance

Transmission and travel damper controller

Power source (signal)

Measure voltage

Between C2 (1),(12) - (11), (21)

Between (6) - (17) Between (6) - chassis

Parking brake ON Parking brake OFF

Between (1) - (3)

20 - 30 V

1. 2. 3. 4.

20 - 30 V


Max. 1 V

Between (1) - (2)

5 - 15 Ω

Between (1), (2) - chassis

Min. 1 MΩ

Between (1) - (2)

5 - 15 Ω


Min. 1 MΩ

Between (1) - (2)

5 - 15 Ω


Min. 1 MΩ

Between (1) - (2)

5 - 15 Ω


Min. 1 MΩ

Between (1) - (2)

5 - 15 Ω


Min. 1 MΩ

Between (1) - (2)

5 - 15 Ω


Min. 1 MΩ

Turn starting switch OFF. Insert T-adapter. Turn starting switch ON. Apply parking brake.

1. Turn starting switch OFF. 2. Disconnect connector. 3. Connect T-adapter. 1. Turn starting switch OFF. 2. Disconnect connector. 3. Connect T-adapter. 1. Turn starting switch OFF. 2. Disconnect connector. 3. Connect T-adapter. 1. Turn starting switch OFF. 2. Disconnect connector. 3. Connect T-adapter. 1. Turn starting switch OFF. 2. Disconnect connector. 3. Connect T-adapter. 1. Turn starting switch OFF. 2. Disconnect connector. 3. Connect T-adapter.

20-13




★ When carrying out operations during inspection, raise the work equipment control lever stand for operations, and lower it when traveling. ★ Turn the starting switch OFF before inserting the T-adapter or making any connections.


Controller


ECMV fill switch

Transmission oil temperature

Controller

Engine speed sensor

Engine speed

Engine speed

20-14

CN13 (male)

4th

CN9 (male)

F

CN17(male)

R

CN15 (male)

CN11 (male)

C2

E04 (male)

C4

—

Measured resistance

3rd

Measured resistance

2nd CN7 (male)

Measured resistance

CN5 (male)

Measured resistance

1st

Inspection method

Measured resistance

Connector no.

Measure voltage

Name of component

Adjust

System

Judgement table If the condition is as shown in the table below, then it is normal Speed lever at measurement position Speed lever not at measurement positions

Directional lever at measurement position Directional lever not at measurement position

Max. 1 Ω Between (1) - chassis Min. 1M Ω

Max. 1 Ω Between (1) - chassis Min. 1 MΩ

Normal temperaBetween ture (25°C) (1) - (2) 100°C

3.8 - 4.8 Ω

1. Turn starting switch OFF. 2. Disconnect connector. 3. Connect T-adapter. 4. Start engine. 5. Place directional lever at N. 6. Turn manual switch ON. 1. Turn starting switch OFF. 2. Disconnect connector. 3. Connect T-adapter. 4. Start engine. 5. Turn transmission cut-off switch OFF (lamp off). 6. Turn parking brake switch OFF. 7. Depress brake. 1. Turn starting switch OFF. 2. Disconnect connector. 3. Connect T-adapter.

3.6 - 3.9 Ω

Normal temperaBetween ture (25°C) (11) - (17) 100°C

4.4 - 4.6 Ω


2.1 - 2.3 Ω

Between (2) - (3)

500 - 1000 Ω


Min. 1 MΩ

Measure with AC range Between (2) - (9)


Max. 0.5 V

1. Turn crank pulley to align the fitting hole of the speed sensor with the flywheel pin. 2. Screw in the speed sensor until its end touches the flywheel pin, then return by 1 turn.

1. Turn starting switch OFF. 2. Disconnect connector. 3. Connect T-adapter. 1. Turn starting switch OFF. 2. Insert T-adapter. 3. Start engine.

—

WF550-3 / WF550T-3




★ When carrying out operations during inspection, raise the work equipment control lever stand for operations, and lower it when traveling.

Name of component

Connector no.

Inspection method

CN3 (male)

Speed

Measure voltage

Speed lever (3rd)

Measure voltage

Speed lever (2nd)

Speed lever (4rd)

Measure voltage

Speed lever (1st)

Measure voltage

—

Directional lever (F)

Measure voltage

Directional lever (R)

Measure voltage

C3B

Directional lever (N)

Measure voltage

Controller


Speed

Adjust

System

Measure resistance

★ Turn the starting switch OFF before inserting the T-adapter or making any connections.

WF550-3 / WF550T-3

Judgement table If the condition is as shown in the table below, then it is normal Between (1) - (2)

500-1000 Ω


Min. 1 MΩ

1. Screw in until speed sensor contacts ring gear, then turn back 1/2 - 1 turn. 2. Sensor should work normally when adjusted as above. Speed control lever at 1st Speed control lever not at 1st

Between (7) - chassis

Speed control lever at 2nd

Between Speed control lever not at 2nd (15) - chassis

Speed control lever at 3rd Speed control lever not at 3rd


20 - 30 V Max. 1 V

20 - 30 V Max. 1 V

20 - 30 V Max. 1 V

Speed control lever at 4th

20 - 30 V Between Speed control lever not at 4th (16) - chassis Max. 1 V

Directional lever at F Directional lever not at F

Directional lever at R Directional lever not at R

Directional lever at N Directional lever not at N


20 - 30 V


20 - 30 V

Max. 1 V

Max. 1 V

20 - 30 V

Between (13) - chassis Max. 1 V

Measurement conditions 1. Turn starting switch OFF. 2. Disconnect connector. 3. Connect T-adapter.

— 1. Turn starting switch OFF. 2. Insert T-adapter. 3. Turn starting switch ON. 1. Turn starting switch OFF. 2. Insert T-adapter. 3. Turn starting switch ON. 1. Turn starting switch OFF. 2. Insert T-adapter. 3. Turn starting switch ON. 1. Turn starting switch OFF. 2. Insert T-adapter. 3. Turn starting switch ON. 1. Turn starting switch OFF. 2. Insert T-adapter. 3. Turn starting switch ON. 1. Turn starting switch OFF. 2. Insert T-adapter. 3. Turn starting switch ON. 1. Turn starting switch OFF. 2. Insert T-adapter. 3. Turn starting switch ON.

20-15





L12 (male)

Measure resistance

L05

L05

Measure voltage

Charge (Alternator)


Hold switch ON

Measure voltage

Hold switch

Judgement table If the condition is as shown in the table below, then it is normal

Kick-down switch ON

L15 (male)

Power source

Between (1) - (2)

Kick-down switch OFF

Between (3) - (4)

Hold switch OFF

Operating normally

Between (1) - (2)

When left brake is depressed

Between (1), (2) - chassis Between (1), (2) - (3)

Engine running (above 1/2 throttle) Starting switch ON

Between (5) - (3)

4-8V

Max. 1Ω

Measurement conditions 1. Turn starting switch OFF. 2. Insert T-adapter. 3. Turn starting switch ON.

1. Turn starting switch OFF. 2. Disconnect connector. 3. Connect T-adapter.

Min. 1 MΩ

Max. 1Ω


Min. 1 MΩ

Max. 1Ω


Min. 1 MΩ

20 - 30 V

28 ± 2 V

1. Turn starting switch OFF. 2. Insert T-adapter. 3. Turn starting switch ON. 1. Turn starting switch OFF. 2. Insert T-adapter.

Max. 1 V

If the battery is old, or after starting in cold areas, the voltage may not rise for some time.

Engine water Temperature sensor

E05 (male)

Measure resistance

Main monitor related

C3B

Kick down switch

Transmission cut-off switch

20-16

Inspection method

Measure resistance

S-NET (between transmission controller and main monitor)

Connector no.

Measure resistance

Name of component Controller


System

Measure voltage


Normal temperature (25°C) 5°C


Approx. 2 kΩ


Approx. 4 kΩ

WF550-3 / WF550T-3





Directional switch (N)

Starting switch terminal C

Connector no.

Inspection method

L05

L09 (male)

Starting switch terminal C

Directional lever not at N

Engine started

Starting switch at OFF or ON

Starting switch at OFF or ON

Measure voltage

Starting switch ON Starting switch OFF

Between (8) - (3)


Between (4) - (3)

Between (19) - (3)

20 - 30 V Max 1 V

20 - 30 V

Measurement conditions 1. Turn starting switch OFF. 2. Insert T-adapter. 3. Turn starting switch ON. 1. Turn starting switch OFF. 2. Connect T-adapter.

Max 1 V

20 - 30 V

1. Turn starting switch OFF. 2. Connect T-adapter.

Max 1 V

★ 20 - 30 V →1V


Max 1 V

★ Changes when water temperature is below 0°C, or

time taken to change differs according to water temperature.

Starting switch ON Preheating output

L06

Measure voltage


Directional lever at N

Starting switch at START

L05 Preheating ON


Measure voltagee

Name of component

Measure voltage

System

Measure voltagee


Starting switch OFF

Between (4) - (16)

★ 1V → 20 - 30 V


Max 1 V

★ Changes when water temperature is below 0°C, or

Measure voltage

Starting switch terminal BR

L07

Parking brake indicator switch

CN19 (male)

Starting switch terminal BR

WF550-3 / WF550T-3

Measure resistance

L09 (male)

Measure voltage

time taken to change differs according to water temperature. Starting switch ON Starting switch OFF

Starting switch ON Starting switch OFF

Parking brake ON Parking brake OFF


20 - 30 V

Between (10) - (12)

20 - 30 V

Between (1) - (2)

Max. 1Ω

Max 1 V

1. Turn starting switch OFF. 2. Disconnect connector. 3. Connect T-adapter. 1. Turn starting switch OFF. 2. Connect T-adapter.

Max 1 V

Min. 1 MΩ


20-17





Directional switch (F)

Judgement table If the condition is as shown in the table below, then it is normal Directional lever at (F) Directional lever not at (F)

Measure voltage

Power source

Measure voltage

Fuel level sensor

Radiator water level sensor

E06 (male)

CN18 (male)

R07 (male)

G01 (male)

Measure resistance

Torque converter oil temperature sensor

L18

Measure resistance

Directional switch (R)

Directional lever at (R) Directional lever not at (R)


20 - 30 V


20 - 30 V

Between (1), (2) - chassis Between (1), (2) - (3)



Measure resistance

Maintenance monitor related

Inspection method

Max 1 V

L08

Engine water temperature sensor

20-18

Connector no.

Measure voltage

Name of component

Measure resistance


System

Water level normal Water level low

Between (1) - (2)

Between (1) - (2)

Max 1 V

1. Turn starting switch OFF. 2. Insert T-adapter. 3. Turn starting switch 1. Turn starting switch OFF. 2. Insert T-adapter. 3. Turn starting switch

20 - 30 V

1. Turn starting switch OFF. 2. Insert T-adapter. 3. Turn starting switch

Approx. 40 kΩ

1. Turn starting switch OFF. 2. Disconnect connectors. 3. Connect T-adapter.

Approx. 1.7 kΩ

Approx. 40 kΩ


Approx. 1.7 kΩ

Float raised to stopper

Approx. 4Ω

Float lowered to stopper

Approx. 85 kΩ

Between (1) - (2)


Max. 1 Ω Min. 1 MΩ

1. 2. 3. 4.

Turn starting switch OFF. Disconnect connectors. Drain fuel. Remove fuel level sensor. 5. Connect T-adapter.


WF550-3 / WF550T-3





System

Name of component

Connector no.

Inspection method


Engine oil pressure sensor

E11

Measure resistance

Engine oil pressure: Min. 0.07 MPa {0.7 kg/cm2} (Start engine) Engine oil pressure with starter switch ON: above 0.03 MPa

Min. 1 MΩ

Measurement conditions 1. Turn starting switch OFF. 2. Disconnect connector. 3. Start engine.

Between (1) - (3) Max. 1 Ω

2

B08 (male) B13 (male)

Measure resistance

Brake accumulator low pressure switch

Accumulator pressure: Min. 5.39 ± 0.49 MPa {55 ± 5 kg/cm2} Depress brake and lower accumulator pressure to below 4.41 ± 0.49 MPa

Max. 1 Ω


Between (1) - (2) Min. 1 MΩ

2

{45 ± 5 kg/cm }

Charge (Alternator)

L18

Measure voltage


{0.3 kg/cm }

Engine running (at above 1/2 throttle) starting switch ON

Between (12) - (3), (14)

28 ± 2 V

1. Turn starting switch OFF. 2. Insert T-adapter. 3. Start engine.

Max 1 V

★ If the battery is old, or after starting in cold areas, the

E10 (male)

Dust indicator

E19 (male) E20 (male)

WF550-3 / WF550T-3

Check continuity

Engine oil level sensor

Measure resistance

voltage may not rise for some time.

Engine oil level normal Engine oil level abnormal

Air cleaner normal Air cleaner clogged or engine stopped no continuity


Between E19(1) E20(1)

Max. 1 Ω

1. Turn starting switch OFF. 2. Disconnect terminal.

Min. 1 MΩ

Continuity No Continuity

1. 2. 3. 4.

Turn starting switch OFF. Disconnect terminal. Start engine. Put tester in contact with connector at sensor end and measure.

20-19





System

Name of component

Connector no.

Inspection method


1. Connect T-adapter.

Table 1 (CHECK, CAUTION portion)


Connector no.

20-20

CHECK, CAUTION portion

L18 (male)

Monitor item (input connector)


Display


Sensor signal input

Engine water level ((8) - (3), (14))

Engine stopped starter switch ON

Flashing

15 - 20 V

OFF

Max. 1 V

Engine oil level ((13) - (3), (14))

Engine stopped starter switch ON

Flashing

15 - 20 V

OFF

Max. 1 V

Engine oil pressure ((10) - (3), (14))

Start engine

Brake oil pressure ((11) - (3), (14))

Start engine

Battery charge ((12) - (3), (14))

Start engine

Air cleaner ((15) - (3), (14))

Start engine

Flashing

15 - 20 V

OFF

Max. 1 V

Flashing

15 - 20 V

OFF

Max. 1 V

Flashing

Max. 10 V

OFF

Min. 12 V

Flashing

15 - 20 V

OFF

Max. 1 V

WF550-3 / WF550T-3





System

Name of component

Connector no.

Inspection method


Table 2 (Gauge portion)

Green 6

Min.

E

Green 4 20.5 - 30.6

Green

←|→

(Ω)

←|

Red 2

Red 1

Green 4

Green 3

102 130°C

Green 2

Green 1

67

Engine water temperature gauge L18 (male)

Max.

ON

Green 3 26.7 - 39.6 Green 2 35.2 - 51.6

F Red

Green 6 0 - 15.7

1. Turn starting switch OFF, then insert dummy resistance or measure resistance of sensor. 2. Turn starting switch ON and check display.

Green 5 12.6 - 24.0 |

Flashing

Min.

Green 1 46.5 - 80.6 Red

73.8 -

Red 2

0.24 - 3.47

Red 1

3.13 - 3.75

Green 4 3.39 - 4.26 |

Green 3 3.85 - 5.14 Green 2 4.65 - 6.94

E

F White |→

Green ON (1 place)

Green 5

Green 4

Green 1 46.5 - 10.26

(kΩ)

White

73.8 -

(1 place)

120 130°C

Green 3

Green 2

Green 1

Max.

← | → Flashing

50

Torque converter oil temperature gauge L18 (male)

Red

Red 2

Measure resistance between (4) - (3), (14)

Red 1

Gauge portion

Green 5

Green 4

Green 3

Green 2

Starting switch OFF

Green 1

Starting switch ON

White



Display level resistance (monitor panel input resistance)

Red

Fuel level gauge L18 (male)

Gauge display position


Min.

Red 2

0.24 - 1.90

Red 1

1.68 - 2.40

Green 5 2.15 - 3.05 |

Green 4 2.74 - 5.14 Green 3 4.65 - 9.39


WF550-3 / WF550T-3

E

F Green |→

ON (1 place)

Red

Max.

Green 2 8.43 - 18.18

(kΩ)

Green 1 15.88 -

← | → Flashing

(1 place)

20-21





Others

Parking brake emergency cancel solenoid

Emergency brake switch

L09

B14

B09 (male) B10 (male)

Inspection method

Measure voltage

Parking brake emergency cancel switch

Connector no.

Measure voltage

Name of component

Measure resistance

System

Judgement table If the condition is as shown in the table below, then it is normal Parking brake emergency cancel switch ON Parking brake emergency cancel switch OFF

Parking brake emergency cancel switch ON Parking brake emergency cancel switch OFF

Accumulator pressure: Min. 3.92 ± 0.49 MPa (40 ± 5 kg/cm2) Depress brake and lower accumulator pressure to below 3.63 ± 0.49 MPa

(1) - (2) and (3) - (4)

20 - 30 V


Max. 1 V

20 - 30 V


Between (2) - (1) Max. 1 V

Between B09 (1) - (2) B10 (1) - (2)

Max. 1 Ω


Min. 1 Ω

2

(37 ± 5 kg/cm )


BR1

Measure voltage

Accumulator pressure: Min. 3.92 ± 0.49 MPa (40 ± 5 kg/cm2) Depress brake and lower accumulator pressure to below 3.63 ± 0.49 MPa

20 - 30 V


Between (7) - (8) Max. 1 V

Bucket positione proximity switch

20-22

F05

Measure voltage

(37 ± 5 kg/cm2)

When screwdriver is brought close

When screwdriver is not brought close

Between (1) - (2)

20 - 30 V

Max. 3 V

Between (1) - (3)

20 - 30 V

20 - 30 V

Between (2) - (3)

Max. 3 V

20 - 30 V


WF550-3 / WF550T-3





F06

Others

Bucket kick-out proximity switch

Connector no.

Bucket kick-out solenoid

Bucket positioner solenoid

WF550-3 / WF550T-3

L16

L17

Inspection method

Measure voltage

Name of component

Measure Measure resistance resistance

System

Judgement table If the condition is as shown in the table below, then it is normal When screwdriver is brought close

When screwdriver is not brought close

Between (1) - (2)

20 - 30 V

Max. 3 V

Between (1) - (3)

20 - 30 V

20 - 30 V

Between (2) - (3)

Max. 3 V

20 - 30 V

Between (1) - (2)

19 - 23 Ω


Min. 1 MΩ

Between (1) - (2)

19 - 23 Ω


Min. 1 MΩ


1. Turn starting switch OFF. 2. Disconnect connectors. 3. Connect T-adapter. 1. Turn starting switch OFF. 2. Disconnect connectors. 3. Connect T-adapter.

20-23



WF550-3 / WF550T-3


Table of required tools

Table of required tools Test, adjustment item

Symbol

Part No.

A

799-203-8001

Engine speed

Part Name

Multi-tachometer

Remarks Digital Display

L: 60-2000 rpm H: 60-19,999 rpm

Kit Part No.: 799-203-9000 Water, oil, exhaust temperatures

799-101-1502

Digital temperature gauge

-99.9 - 1,299°C

799-101-5002

Hydraulic tester

Pressure gauge

790-261-1203

Digital hydraulic tester

Pressure gauge: 68.6 MPa {700 kg/cm²}

2

799-401-2320

Hydraulic gauge

1.0 MPa {10 kg/cm²}

1

795-502-1590

Compression gauge

2

795-502-1500

Adapter

0 - 6.9 MPa {0 - 70 kg/cm²} Kit Part No.: 795-502-1205

1

799-201-1504

Blow-by checker

2

799-201-1590

Gauge

Commercially available

Feeler gauge

1

799-201-9000

Handy Smoke Checker

2


Smoke meter

799-201-2202

Pressure gauge

793-520-1805

Brake test kit

—

793-520-1851

Nipple

—

B

1 Oil pressure

Compression pressure

Blow-by pressure

C

D

E

Valve clearance

Exhaust color

F

G

Air supply pressure (boost pressure)

H

Brake oil pressure

I 79A-264-0020

Operating effort

J

2.5,5.9,39.2,58.8 MPa {25,60,400,600 kg/cm²}

— 0 - 98 kPa {0 - 1,000 mmH2O} — Discoloration 0 - 70% (with standard color) (Discoloration × 1/10

-101.3 - 199.9 kPa {-760 - 1,500 mmHg}

0 - 294.2 N {0 - 30 kg} Push-pull scale

79A-264-0090

0 - 490.3 N {0 - 50 kg}

Stroke, hydraulic drift

K


Scale

—

Work equipment Speed

L


Stopwatch

—

Measuring brake disc wear

M


Calipers

—

Moving machine when there is failure in transmission valve

N

793T-685-1110

Plate

—

Measuring voltage, resistance value

O

79A-264-0211

Tester

—

799-601-7400

T-adapter assembly

—

1

799-601-7310 Troubleshooting of wiring harness, sensors

WF550-3 / WF550T-3

Bosch index)

P

SWP12P

799-601-7320 2

SWP16P Adapter

799-601-7340

M8P

799-601-7380

JFC2P

20-101

Sketch of special tools


Sketch of special tools Tool N

Komatsu cannot accept any responsibility for special tools manufactured according to these sketches.

20-102

WF550-3 / WF550T-3


Measuring blow-by pressure

Measuring blow-by pressure ★ Raise the coolant temperature to the operating range before measuring.

1. Install blow-by checker E1 to the end of engine breather hose, then connect gauge E2 (0-9.8 kPa {0-1,000 mmH2O}) 2. Run the engine at full throttle, relieve the blade cylinder and measure the blow-by pressure.

NOTE When measuring, be careful not to touch any hot or rotating parts. ★ Blow-by varies greatly according to the condition of the engine. Therefore, if the blow-by value is considered abnormal, check for problems connected with defective blow-by, such as excessive oil consumption, defective exhaust gas color, and prematurely dirty or deteriorated oil.

WF550-3 / WF550T-3

20-103

Measuring engine oil pressure


Measuring engine oil pressure ★ Measure the engine oil pressure under the following conditions. Coolant temperatures: Within operating range

1. Remove engine oil pressure pick-up plug (1) (PT 1/8), then install the adapter and oil pressure gauge C2 (1.0 MPa {10 kg/cm2}) from oil pressure gauge kit C1. 2. Start the engine, and measure the oil pressure at low idling and high idling.

20-104

WF550-3 / WF550T-3


Adjusting speed sensor

Adjusting speed sensor Engine speed sensor 1. Before mounting the engine speed sensor (1), rotate the crank pulley so that the center of the mounting hole and the pin of the flywheel are in accord. 2. When mounting the speed sensor (1), screw it until the top of speed sensor touches the pin (2) of flywheel. 3. When sensor (1) contacts pin (2), turn back 1 turn. ★ Clearance between engine speed sensor (a): 1 +0.2 mm 0

4. Tighten locknut (3). t Locknut: 49 ± 4.9 Nm {5.0 ± 0.5 kgm} ★ Be particularly careful when handling the sensor wiring to ensure that no excessive force is brought to bear on the wiring. ★ Be careful not to let the tip of the sensor be scratched or to let any iron particles stick to it.

Transmission output shaft speed sensor 1. Screw in until the tip of sensor (1) contacts gear. 2. When sensor contacts gear, turn back 1/2-1 turn. 3. Tighten locknut. t Locknut: 49 ± 4.9 Nm {5.0 ± 0.5 kgm} ★ Be particularly careful when handling the sensor wiring to ensure that no excessive force is brought to bear on the wiring. ★ Be careful not to let tip of the sensor be scratched or let any iron particles stick to it.

WF550-3 / WF550T-3

20-105

Adjusting of engine stop motor cable


Adjusting of engine stop motor cable 1. Temporarily install ball joint (3) to cable (2) of engine stop motor (1) (screw in fully, then turn back approx. 1/2 turns), then install the ball joint (3) to the stop lever (4) of the injection pump. 2. Pull stop lever (4) of the injection pump by hand to the engine stop position (no injection of fuel), and temporarily assembly the cable to the bracket (7). When this is done, secure the cable at a point where stop lever (4) contacts engine STOP stopper (5), and temporarily assemble to the bracket with locknut (6). ★ Engine stop motor (1) is at the engine STOP position with cable (2) pulled.

3. Adjust stop lever (4) of the injection pump and STOP stopper (5) at the stop end so that clearance a is 0.5 - 1.5 mm. Adjust with nut (6) which secures the cable to the bracket or carry out fine adjustment by changing the depth that ball joint (3) is screwed in. 4. Tighten all nuts and bolts. 5. Turn the engine starting switch repeatedly to the ON and OFF positions, and check that the engine stop motor and cable works smoothly, then carry out the following checks again. a. Check visually that there is slack in the engine stop motor cable when the engine is running, and that the stop lever of the fuel injection pump has returned fully to the RUN position. b. Check that the clearance between the stop lever and stopper at the STOP end is 0.5 - 1.5 mm when the engine is stopped. ★ With the engine stop motor, there are built-in limit switches at both ends of the cable stoke ★ Engine stop motor stroke: 35 mm ★ Fuel injection pump stop lever stroke: 30.3 mm ★ When the engine is running, there is slack in the engine stop motor cable, and the RUN position is maintained by the action of a spring (this is frequently built into the fuel injection pump). ★ There is a loose spring inside the engine stop motor, and this absorbs the error in the stop motor when the engine is stopped. ★ However, if this is absorbed by the loose spring in the engine stop motor, force is brought to bear on the injection pump, so depending on the machine model, this system may not be possible to use.

20-106

WF550-3 / WF550T-3


Adjusting of engine stop motor cable

★ With such models, there is a danger of problems arising with the injection pump if the clearance between the stop lever and the stopper at the STOP end is set to 0 when the engine is stopped. ★ Problems caused by improper adjustment of engine stop motor cable.

•

When engine stop motor cable is pulled and clearance between stop lever and STOP stopper is too large.

•

When cable is free and clearance between stop lever and RUN stopper is too large.

•

Engine does not stop.

•

Engine does not give full output because of drop in amount of fuel injected.

WF550-3 / WF550T-3

20-107

Torque converter and transmission oil pressure


Torque converter and transmission oil pressure 1. Measuring main relief oil pressure ★ Torque converter oil temperature: 60 - 80°C

a. Remove the cover at the front of the engine and the cover at the rear of the operator’s cab. b. Remove oil pressure measurement plug (1) (PT 1/8), then install oil pressure gauge C1 (5.9 MPa {60 kg/cm2}).

c.

20-108

Start the engine and measure the oil pressure with the engine at low idling and high idling.

WF550-3 / WF550T-3



2. Adjusting main relief valve

Adjust the main relief valve with the engine stopped.

If the main relief pressure is not within the standard value, adjust as follows. a. Remove plug (1) and washer (2). b. Remove inner spring (3) and outer spring (4). c.

Adjust by changing the thickness of shim (5). ★ Standard shim thickness: 3.0 mm (0.5 × 6) ★ Amount of adjustment for one shim: 0.04 MPa {0.4 kg/cm²}

3. Measuring torque converter relief (inlet port) pressure. ★ Torque converter oil temperature: 60 - 80°C

a. Remove the cover at the front of the engine and the cover at the rear of the operator’s cab. b. Remove oil pressure measurement plug (PT 1/8) (1), then install oil pressure gauge C1 (5.9 MPa {60 kg/cm2}). c.

Start the engine and measure the oil pressure with the engine at high idling.

WF550-3 / WF550T-3

20-109



4. Measure torque converter outlet port pressure ★ Torque converter oil temperature: 60 - 80°C

a. Remove the cover at the left side of the transmission. b. Remove oil pressure measurement plug (1) at the bottom of the torque converter oil temperature sensor, then install oil pressure gauge C1 (5.9 MPa {60 kg/cm2}). ★ Oil will leak, so use an oil pan to catch it.

c.


5. Measuring ECMV output (clutch) pressure ★ Torque converter oil temperature: 60 - 80°C

a. Remove the oil pressure measurement plug for the clutch to be measured. •

Plug for measuring 1st clutch pressure: (1)

•

Plug for measuring 2nd clutch pressure: (2)

•

Plug for measuring 3rd clutch pressure: (4)

•

Plug for measuring 4th clutch pressure: (3)

•

Plug for measuring reverse clutch pressure: (5)

•

Plug for measuring forward clutch pressure: (6)

r : Gasket sealant (LG-5) b. Install oil pressure gauge C1 (5.9 MPa/ {60 kg/cm2}). c.

Start the engine and measure the 1st, 2nd, 3rd, and 4th clutch pressures under the following conditions at high idling. I.

Leave the directional lever at Neutral.

II. Turn the main monitor manual switch ON. III. Place the gearshift lever at the speed range to be measured.

20-110

WF550-3 / WF550T-3



d. Start the engine and measure the forward and reverse clutch pressures under the following conditions at high idling.

Put blocks under the tires and depress the brake securely.

I.

Turn the transmission cut-off selector switch OFF (lamp off).

II. Turn the parking brake switch OFF. III. Depress the brake. IV. Place the gearshift lever in 4th. V. Keep the brake depressed and place the directional lever at F or R. 6. Measuring lubricating oil pressure (oil cooler outlet port) ★ Torque converter oil temperature: 60 - 80°C

a. Remove the cover at the left side of the rear frame. b. Remove oil pressure measurement plug (1), then install oil pressure gauge C1 (5.9 MPa {kg/cm2}). c.


WF550-3 / WF550T-3

20-111

Steering oil pressure


Steering oil pressure ★ Hydraulic oil temperature: 45 - 55°C

Measuring 1. Measuring steering relief pressure

Install the safety bar to the frame.

a. Remove oil pressure measurement plug (PT 1/8) (1) from the elbow at the right steering cylinder head end, then install oil pressure gauge C1 (39 MPa {400 kg/cm²}). b. Start the engine, run the engine at high idling, then turn the steering wheel to the right and measure the pressure when the relief valve is actuated. ★ When removing the oil pressure measurement plug on the left steering cylinder, turn the steering wheel to the left.

20-112

WF550-3 / WF550T-3



2. Measuring steering pilot pressure.

Install the safety bar to the frame.

a. Disconnect pilot hose (2) or (3) from steering valve (1).

b. Install the adapter and oil pressure gauge (5.9 MPa {60 kg/cm2}) inside tool C1.

c.

Start the engine and measure the oil pressure when steering wheel is turned with the engine running at high idling. ★ Hose (2): Turn steering to left. ★ Hose (3): Turn steering to right.

WF550-3 / WF550T-3

20-113



Adjusting

Always stop the engine before adjusting the pressure.

1. Adjusting steering relief valve Loosen locknut (2) of steering relief valve (1), the turn adjustment nut (3) to adjust. ★ Turn the adjustment screw to adjust the set pressure as follows.

•

To INCREASE pressure, turn CLOCKWISE.

•

To DECREASE pressure, turn COUNTER CLOCKWISE.

★ Pressure adjustment for one turn of adjustment screw: Approx. 14.8 MPa {151 kg/cm2}

20-114

WF550-3 / WF550T-3


Measuring parking brake oil pressure

Measuring parking brake oil pressure 1. Measuring parking brake inlet port pressure ★ Torque converter oil temperature: 60 - 80°C

a. Remove the transmission side cover. b. Remove oil pressure measurement plug (PT 1/8) (1), then install oil pressure gauge C1 (5.9 MPa {60 kg/cm2}). c.

Turn the parking brake switch OFF.

d. Start the engine and measure with the engine running at low idling and high idling.

2. Measuring parking brake pilot pressure ★ Torque converter oil temperature: 60 - 80°C

a. Open the front cover of the engine and remove the top cover of the transmission. b. Disconnect hose (1), then install adapter and oil pressure gauge in tool C1 (5.9 MPa {60 kg/cm2}). c.

Start the engine and measure at high idling.

WF550-3 / WF550T-3

20-115

Measuring parking brake oil pressure


3. Measuring parking brake solenoid valve output pressure ★ Torque converter oil temperature: 60 - 80°C

a. Remove the cover at the front of the engine and the cover at the top of the transmission. b. Disconnect hose (1), then install adapter and oil pressure gauge in tool C1 (5.9 MPa {60 kg/cm2}). c.

Turn the parking brake switch OFF.

d. Start the engine and measure at high idling.

20-116

WF550-3 / WF550T-3


Testing and adjusting PPC oil pressure

Testing and adjusting PPC oil pressure ★ Hydraulic oil temperature: 45 - 55°C

Measuring 1. Measuring PPC pump pressure a. Open the front cover of the engine. b. Remove oil pressure measurement plug (PT 1/8) (1), then install oil pressure gauge C1 (39 MPa {400 kg/cm2}). c.

Start the engine and measure the oil pressure at high idling.

2. Measuring PPC valve basic pressure (orbit-roll basic pressure) a. Disconnect hose (1), then install the adapter and oil pressure gauge (5.9 MPa {60 kg/cm2}) in tool C1.

WF550-3 / WF550T-3

20-117



b. Start the engine, run the engine at high idling, then operate the work equipment control lever and measure the oil pressure.

3. Measuring PPC valve output pressure

• Loosen the oil filler cap slowly to release the pressure inside the hydraulic tank. • Operate the control levers several times to release the pressure in the PPC accumulator circuit.

WF550-3 a. Remove the main control valve cover. b. Remove oil pressure detection plug (PT 1/8) of the circuit to be measured, then install oil pressure gauge C1 (5.9 MPa {60 kg/cm2}). ★ Plug A: Boom LOWER, Boom FLOAT Plug B: Boom RAISE Plug C: Boom DUMP Plug D: Bucket TILT

c.

20-118

Start the engine, run the engine at high idling, then operate the work equipment control lever and measure oil pressure.

WF550-3 / WF550T-3



WF550T-3 a. Remove the main control valve cover. b. Remove oil pressure detection plug (PT 1/8) of the circuit to be measured, then install oil pressure gauge C1 (5.9 MPa {60 kg/cm2}). ★ Plug A: Blade LOWER, Blade FLOAT ★ Plug B: Blade RAISE

c.

Start the engine, run the engine at high idling, then operate the work equipment control lever and measure oil pressure.

Adjusting 1. Adjusting PPC relief valve Loosen locknut (2) of PPC relief valve (1), then turn adjustment screw (3) to adjust. ★ Turn the adjustment screw to adjust as follows.

•

To INCREASE the pressure, turn CLOCKWISE.

•

To DECREASE the pressure, turn COUNTER CLOCKWISE.

★ Amount of adjustment for one turn of adjustment screw: (1.8 MPa {18.3 kg/cm2})

t Locknut: 83.4 ± 4.9 Nm {8.5 ± 0.5 kgm} ★ After completion of the adjustment, re-check the accumulator charge cut-in pressure and cut-out pressure again referring to section 20 "Testing and Adjusting Accumulator charge pressure" of the WA500-3 Shop manual.

WF550-3 / WF550T-3

20-119

Adjusting PPC valve linkage


Adjusting PPC valve linkage 1. Remove cover at the bottom of the work equipment control lever. 2. Adjust dimension a from nut (1) of the PPC valve linkage to the top surface of the floor. •

Dimension a (target value): 54 mm

3. Loosen nuts (2) and (3), then adjust the installed height of trunnion (5) so that there is no play in lever (4). 4. After adjusting, tighten nuts (2) and (3). WF550-3

WF550T-3

20-120

WF550-3 / WF550T-3


Work equipment hydraulic pressure

Work equipment hydraulic pressure For the WF550-3, see the shop manual for the WA500-3, Serial No. 50001 and up. WF550T-3 ★ Hydraulic oil temperature: 45 - 55°C

• Loosen oil filler cap slowly to release the pressure inside the hydraulic tank. • Operate the control lever 2 - 3 times to release the residual pressure from the piping. 1. Remove the oil pressure pickup plug (PT 1/8) (1) from the lift cylinder circuit.

2. Install the nipple and oil pressure gauge (39 MPa {400 kg/cm2}) contained in tool C1. 3. Start the engine and raise the blade. Run the engine at full throttle to turn on the relief valve and measure the blow-by pressure. ★ Take care not to apply pressure sharply to the pressure gauge.

After measuring, repeat the procedure used when installing the oil pressure gauge to release the pressure inside the circuit, then remove the oil pressure gauge.

WF550-3 / WF550T-3

20-121

Work equipment hydraulic pressure


Adjusting

When adjusting hydraulic pressure, be sure to stop the engine.

1. Remove the front cover of the work equipment valve. 2. Remove cap nut (2) of relief valve (1) and loosen locknut (3). 3. Adjust the pressure by turning adjustment screw (4). ★ If the adjustment screw is

•

turned clockwise, the pressure is increased

•

turned counter clockwise, the pressure is lowered

★ Pressure changed by 1 turn of adjustment screw: Approx. 3.50 MPa {35.7 kg/cm2} ★ If the relief pressure cannot be adjusted accurately, do not adjust it.

4. Tighten locknut (3) and install cap nut (2). t Locknut/Cap nut: 28 - 34.3 Nm {2.8 - 3.5 kgm} 5. After finishing adjustment, measure the relief pressure of the work equipment again. For details, see above "WORK EQUIPMENT HYDRAULIC PRESSURE".

20-122

WF550-3 / WF550T-3


Adjusting work equipment lever linkage

Adjusting work equipment lever linkage For the WF550-3, see the shop manual for the WA500-3, Serial No. 50001 and up. WF550T-3 ★ Always stop the engine before adjusting the work equipment lever linkage. ★ Check that the operating effort of the work equipment control lever is within the standard value.

RAISE FLOAT

1. Adjust clearance A and the height of rod (4) so that cam follower (2) will be fitted to the detent of cam (3) and the play of the detent will be eliminated when lever (1) is set to the FLOAT BLADE position. Clearance A: 0 - 1 mm Standard height B of rod (4): 337 mm 2. Adjust the position of lock lever bracket (5) so that lever (1) can be locked to the neutral position.

WF550-3 / WF550T-3

20-123

Adjusting main monitor (speedometer module)


Adjusting main monitor (speedometer module) •

The speedometer on the main monitor is a common part for all machines, and the input signal for the travel speed differs according to the machine, so it is necessary to adjust the monitor for use with the particular model.

•

Since rims of different types have different diameters, the monitor needs to be adjusted for the rims installed.

Adjustment procedure Turn off the power, then remove the machine monitor and adjust the switches at the back of the speedometer.

Rear of main monitor

1. Setting machine model a. Remove the rubber caps from dip switches (1), (2) and (3) at the back of the speedometer.

Turn

Rotary switch

b. When the rubber cap is removed, a rotary switch can be seen inside. Using a flat-headed screwdriver, turn this switch to adjust it to the setting in the table below.

Wheel size

Switch 1 (model selection)

Switch 2 (speedometer correction)

Switch 3 (tachometer input selection)

Triangular foot type (Standard)

5

7

0

Chopper type (Optional)

5

7

0

Adjust point

20-124

WF550-3 / WF550T-3


Adjusting main monitor (speedometer module)

Reference: Amount of correction for switch (2) Switch position

0

1

2

3

4

5

6

7

Amount of correction (%)

+14

+12

+10

+8

+6

+4

+2

0

Switch position

8

9

A

B

C

D

E

F

Amount of correction (%)

0

-2

-4

-6

-8

-10

-12

-14

c.

After completing the adjustment, fit the rubber caps securely and install the main monitor.

WF550-3 / WF550T-3

20-125



WF550-3 / WF550T-3

TROUBLESHOOTING Outline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20-202 Connector types and mounting locations 20-203 Connector arrangement diagram . . . . . . . 20-206 ★ For items other than the above, see WA500-3, serial No. 50001 and up.

WF550-3 / WF550T-3

20-201

Outline

TROUBLESHOOTING

Outline The changed points of the electric circuit of WA500-3 are shown below. For the points other than the following changed points, see "Troubleshooting" for WA500-3. 1. Elimination of boom kick-out function and bucket positioning function (WF550T-3 only) Parts removed for elimination of above functions. a. Proximity switch for boom kick-out (F06) b. Proximity switch for bucket positioner (F05) c.

Boom relay (L49)

d. Bucket relay (L48) 2. Elimination of travel damping function (Optional function is eliminated, too) Parts removed for elimination of above function a. ECSS relay (L91) 3. Elimination of work equipment control function (Optional function is eliminated, too) 4. Elimination of headlamps and front combination lamps on both sides Parts removed for elimination of above items a. (1) Right headlamp (F01) b. (2) Left headlamp (F04) c.

(3) Right front combination lamp (F02)

d. (4) Left front combination lamp (F03) e. (5) Turn signal unit (L46) 5. Change of air conditioner condenser Elimination of electric motor fan. 6. Addition of rotating direction control function of radiator fan Change to hydraulic cooling fan 7. Addition of working lamp on cab 8. Elimination of transmission controller auto-shift function

20-202

WF550-3 / WF550T-3

TROUBLESHOOTING

Connector types and mounting locations

Connector types and mounting locations ★ The address column in the table below shows the address in the connector arrangement drawing (3-dimensional drawing)

: Items for WF550 only Connector No.

Type

No. of Pins

A4

X

2

A5

M

A6

SWP

A7

M

Address

Connector No.

Type

No. of Pins

Air servo motor

A4

C03

M

2

Front working lamp (R.H.)

N8

2

Thermistor

A5

C04

M

2

Front working lamp (L.H.)

O9

6

Air mix servo motor

A6

C05

4

Warning lamp switch

N8

6

Blower motor

A7

C06

KES 1

2

Room lamp

O9

A8A

C07

M

4

Rear wiper motor

Q7

A8B

C1

MIC

13

Trans. & ECSS controller

M2


M1

Place of use

Place of use

Address

A8A

S

10

Intermediate connector (air conditioner relay)

A8B

S

8

Intermediate connector (air conditioner relay)

A9

Yazaki

4

Blower relay (main)

A9

C2

MIC

21

A10

Yazaki

4

Blower relay (Hi)

A10

C3A

AMP040

20


N1

A11

Yazaki

4

Blower relay (M2)

A11

C3B

AMP040

16


N2

A12

Yazaki

4

Condenser relay

A12

C4

AMP040

12


N1

A13

Yazaki

4

Blower relay (M1)

R3

C5

MIC

17


N1

A14

X

2

Air conditioner switch

R5

CL1

S

12

Intermediate connector (working lamp, radio)

M3

A14

Yazaki

4

Condenser relay (Hi)

R4

CL2

S

10

Intermediate connector (air conditioner)

M3

A15

Yazaki

2

Hi/Lo switch

R5

CL3

M

6

Intermediate connector (air conditioner)

M2

A15

Yazaki

4

Air conditioner relay (Hi)

R3

CL4

M

3

Intermediate connector (working lamp)

M3

A16

Yazaki

4

Magnet clutch relay

R3

CN3

X

2

Speed sensor

G1

A16

SWP

12

Air conditioner controller

N2

CN4

JFC

2

1st solenoid

C7

A17

SWP

16

Air conditioner controller

N2

CN5

X

1

1st fill switch

B9

A18

SWP

8

L.H. detection servo motor

—

CN6

JFC

2

2nd solenoid

D7

A19

SWP

8

R.H. detection servo motor

—

CN7

X

1

2nd fill switch

C9

B03

KES 1

2

Window washer (front)

H9

CN8

JFC

2

4th solenoid

D7

B04

KES 1

2

Window washer (rear)

H9

CN9

X

1

4th fill switch

C9

B05

KES 1

2

Diode

—

CN10

X

2

Parking brake solenoid

D8

B06

KES 1

2

Diode

—

CN11

X

2


H1

B08

X

2


I2

CN12

JFC

2

3rd solenoid

D7

B09

X

2


G9

CN13

X

1

3rd fill switch

C9

B10

X

2


G9

CN14

JFC

2

R solenoid

E8

B13

X

2


I2

CN15

X

1

R fill switch

D9

B14

X

2

Parking brake emergency release solenoid

G9

CN16

JFC

2

F solenoid

E8

BR1

SWP

14

Intermediate connector (washer, condenser)

I2

CN17

X

1

F fill switch

D9

C01

M

6

Front wiper motor

N2

CN18

X

2

Torque converter oil temperature sensor

H1

WF550-3 / WF550T-3

20-203


Connector No.

Type

No. of Pins

Place of use

TROUBLESHOOTING

Address

Connector No.

Type

No. of Pins

Place of use

Address

9

Radio

M4

CN19

X

2

Parking brake indicator switch

H1

—

1

Slow blow fuse

L2

FS4

L

2

Power source

R7

E02

—

1

Slow blow fuse

L2

FS5

M

6

Fuse

R7

E03

SWP

8

Engine stop motor

H9

FS6

M

4

Fuse

R7

E04

X

3

Engine speed sensor

J3

G01

X

2

Coolant level

K9

1

Engine water temperature sensor (Std specification)

L8

G02

M

2

Working lamp (RH)

J9

C01 E01

E05 E06

X

2

Engine water temperature sensor (Std specification)

L4

G03

M

2

Working lamp (LH)

K9

E07

—

1

Heater relay

I9

GND

1 Pin conn.

1

Intermediate connector

N2

E08

—

1

Heater relay

I9

GR1

X

4

Intermediate connector (working lamp)

L7

E09

—

1

Heater relay

I9

GRE

SWP

6

Grease

—

E10

X

1

Engine oil level sensor

K3

IND

2

Reverse indicator lamp (flashes)

M6

E11

—

1

Engine oil pressure sensor

L8

JS1

1

Buzzer

R5 P2

S

E12

X

1

Air conditioner compressor

J9

JS12

M

3

Intermediate connector (joystick switch)

E13

X

2

Starting motor

L4

JS14

M

8

Intermediate connector (joystick lever switch)

P2

E15

—

1

Alternator terminal B

L7

L01

SWP

6


M5

E16

—

1

Alternator terminal R

L5

L02

SWP

6

Light & dimmer switch

M5

E17

—

1

Alternator terminal E

L6

L03

SWP

6

Turn signal & hazard switch

M5

E19

1 pin conn.

1

Dust indicator

H9

L04

SWP

14

F/R & speed switch

M3

E20

1 Pin conn.

1

Dust indicator

I9

L05

AMP040

20

Main monitor

M5

E23

KES 1

2

Diode

—

L06

AMP040

16

Main monitor

M4

J2

L07

AMP040

12

Main monitor

M4

ER1

SWP

14

Intermediate connector (air conditioner, engine water temperature sensor)

ER2

SWP

8

Intermediate connector (engine stop motor)

J2

L08

AMP040

8

Main monitor

M4

EST

X

3

Remove when installing emergency steering

—

L09

M

4

Starting switch

M4

F05

X

3

Bucket positioner

D6

L10

S

10

Wiper switch

M4

F06

X

3

Boom kick-out

E7

L12

X

2

Transmission cut-off switch

P2

F07

—

1

Horn

D6

L15

M

4

Kick-down & hold switch

M7

F08

—

1

Horn

D1

L16

KES 1

2

Boom kick-out solenoid

M7

F09

—

1

Horn

E1

L17

KES 1

2

Bucket positioner solenoid

M6

F10

—

1

Horn

E7

L18

AMP040

16

Maintenance monitor

M7

FL

KES 1

4

Flasher unit

Q8

L19

AMP040

8

Maintenance monitor

M6

FR1

S

10

Intermediate connector (horn)

G1

L21

KES 1

2

Maintenance monitor

M7

FS1

L

2

Power source

R6

L22

KES 1

2

Maintenance monitor

M7 M5 M6

FS2

S

12

Fuse

R6

L32

M

2

Intermediate connector (power source, GND)

L34

S

8

Intermediate connector (network, buzzer output)

O2

L33

M

2

Intermediate connector (boom kick-out output)

20-204

WF550-3 / WF550T-3

TROUBLESHOOTING


Address

Connector No.

Type

No. of Pins

Caution buzzer

O9

OP1

1 Pin conn.

1

Fuse outlet

R6

1

Caution buzzer

P9

OP2

1 Pin conn.

1

Fuse outlet

R5

KES 0

6

Wiper relay

R7

R07

X

2

Fuel level sensor

K3

Relay

5

Bucket relay

R8

R08

M

6

Rear combination lamp (LH)

L6

Connector No.

Type

No. of Pins

L42

1 Pin conn.

1

L43

1 Pin conn.

L44 L48 L49 L52

Place of use

Place of use

Address

Relay

5

Boom relay

R8

R09

M

6

Rear combination lamp (RH)

J9

Relay

5

Hazard relay

Q8

R11

Terminal

1

Battery

K9

L53

Relay

5

Stop lamp relay

R8

R12

Terminal

1

Battery relay

K1

L54

Relay

5

Backup lamp relay

R8

R13

Terminal

1

Battery relay

K1

L55

Relay

5

Horn relay

R8

R15

Terminal

1

Slow blow fuse

L3

L56

Relay

5

Preheating relay

R9

R17

Terminal

2

Slow blow fuse

L1

L57

Relay

5

Neutral relay

Q8

R18

1 Pin conn.

1

License lamp

L7

L58

Relay

5

Neutralizing relay

Q9

R19

1 Pin conn.

1

License lamp (GND)

L7

L59

Relay

5

Parking brake safety relay

Q9

RH1

SWP

6

Intermediate connector

B8

L60

Relay

6

Front working lamp relay

R9

SEL1

M

2

Engine select

O2

L61

Relay

6

Rear working lamp relay

R9

SLa

X

2

Solenoid valve

G9

L62

Relay

5

Engine stop relay

Q9

SLb

X

2

Solenoid valve

G9

L63

1 Pin conn.

1

Horn switch

M5

SW1

DT

3

Auto/Manual selector switch

M9

L64

Relay

5

Engine oil pressure relay

Q9

SW2

DT

3

Forward/Reverse selector switch

M9

L80

Relay

5

Dust indicator relay

Q9

TM1

—

8

Timer

N9 B6

L81

X

2

Stop lamp switch

O2

TM1

SWP

14

Intermediate connector (transmission)

L90

KES 1

4

Parking brake emergency release switch

R5

TM2

SWP

16

Intermediate connector (transmission)

A6

LFL

Relay

5

Flasher unit relay

Q2

TM2

—

8

Timer

N2

LR1

S

12

Intermediate connector (lamp)

B7

TM3

—

8

Timer

O2

LR2

SWP

14

Intermediate connector (air conditioner, washer)

A7

LR3

SWP

8

Intermediate connector (engine stop motor)

B6

LR4

SWP

14

Intermediate connector (monitor related)

A7

LR5

X

4

Intermediate connector (power source, GND)

B6

LR6

L

2

Intermediate connector (power source)

A6

LSL

Relay

5

Revolving direction relay

Q2

LTM

Relay

5

Timer relay

Q2

WF550-3 / WF550T-3

20-205

Connector arrangement diagram

TROUBLESHOOTING


20-206

WF550-3 / WF550T-3

TROUBLESHOOTING

WF550-3 / WF550T-3


20-207


20-208

TROUBLESHOOTING

WF550-3 / WF550T-3

TROUBLESHOOTING


WF550-3 / WF550T-3

TROUBLESHOOTING


WF550-3 / WF550T-3

TROUBLESHOOTING FOR RADIATOR COOLING FAN SYSTEM (EC MODE) Electric circuit diagram of cooling fan system . . . . . . . . . . . . . . . . . . . 20-252 EC-1 Fan does not rotate (selector switch position: AUTO) . . . . . . . 20-254 EC-2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20-258 Fan does not rotate (selector switch position: MANUAL) . . . . . . . 20-258 EC-3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20-262 Fan does not switch from forward to reverse rotation (selector switch position: AUTO) . . . . . . . . . 20-262 EC-4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20-263 Fan does not switch from forward to reverse rotation (selector switch position: MANUAL) . . . . . . . 20-263 EC-5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20-264 Fan does not switch from reverse to forward rotation (selector switch position: AUTO) . . . . . . . . . 20-264 EC-6 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20-265 Fan does not switch from reverse to forward rotation (selector switch position: MANUAL) . . . . . . . 20-265 EC-7 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20-266 When direction of fan is switched, it immediately switches . . . . . . . . . . . . . . . . 20-266

★ Before carrying out troubleshooting, check that all the related connectors are properly inserted. ★ Always connect any disconnected connectors before going on to the next step.

WF550-3 / WF550T-3

20-251

Electric circuit diagram of cooling fan system

TROUBLESHOOTING FOR RADIATOR COOLING FAN SYSTEM (EC MODE)

Electric circuit diagram of cooling fan system Flasher unit relay

Timer relay

Revolving direction relay

Flasher unit

Reverse indicator lamp diode (flashes)

Auto/manual selector switch

Forward/reverse selector switch

Timer 3

Timer 2

Timer 1

Fuse box

Fan direction control valve

20-252

WF550-3 / WF550T-3


Electric circuit diagram of cooling fan system


WF550-3 / WF550T-3

20-253

EC-1 Fan does not rotate (selector switch position: AUTO)


EC-1 Fan does not rotate (selector switch position: AUTO) 1. Does not rotate in forward direction Cause

Remedy

1 • 20 - 30V • Disconnect SW1. • Turn starting switch ON.

Is voltage between SW1 (2) (female) and chassis normal?

NO

YES • • • •

Max 1 Ω Turn starting switch OFF. Switch (SW1) position: AUTO Disconnect SW1.

2 Is resistance between SW1 (male) (2) and (3) normal?

NO

Defective AUTO / MANUAL selector switch

Replace

Defective contact or disconnection in wiring harness between SLb (female) (2) and chassis ground

Repair or replace

Defective contact or disconnection in wiring harness between LTM (female) (5) and SLb (female) (1)

Repair or replace

Defective contact or disconnection in wiring harness between TM3 (female) (4) and LTM (female) (1)

Repair or replace

Defective contact or disconnection in wiring harness between SW1 (female) (3) and TM1 (female) (1), (7), (8)

Repair or replace

Defective contact or disconnection in wiring harness between TM1 (female) (4), (5) and TM3 (female) (1), (7)

Repair or replace

Defective relay (LTM)

Replace

YES 3 • • • •

20 - 30V Disconnect SLb. Turn starting switch ON. Switch (SW1) position: AUTO (Wait for at least 15 seconds before measuring.)

Is voltage between SLb (female) (1) and chassis normal?

NO

Voltage flows only during time of rotation in forward direction set as desired by timer (TM1). YES

4 • Max 1 Ω • Turn starting switch OFF. • Disconnect LTM and SLb.

Is resistance between LTM (female) (5) and SLb (female) (1) normal?

NO

YES 5 • Max 1 Ω • Turn starting switch OFF. • Disconnect TM3 and LTM3.

Is resistance between TM3 (female) (4) and LTM (female) (1) normal?

NO

YES 6 • Max 1 Ω • Turn starting switch OFF. • Disconnect SW1 and TM1.

Is resistance between SW1 (female) (3) and TM1 (female) (1), (7), (8) normal?

NO

YES 7 • Max 1 Ω • Turn starting switch OFF. • Disconnect TM1 and TM3.

Is resistance between TM1 (female) (4), (5) and TM3 (female) (1), (7) normal?

NO

YES 8 • Replace with relay (LFL).

Does condition become normal when relay (LTM) is replaced?

NO

YES

Go to next page

20-254

Go to next page

WF550-3 / WF550T-3


From previous page


Cause

From previous page

Remedy

9 • Replace with timer (TM2).

Does condition become normal when timer (TM3) is replaced?

NO

YES

Defective timer (TM3)

Replace

Defective solenoid valve

Replace


Replace

Defective fuse or power circuit

Repair or replace

Defective contact or disconnection in wiring harness between OP2 (male) and SW1 (female) (2)

Repair or replace

10 • Replace timer (TM1) with new part.


NO

YES

11 • 20 - 30 V • Disconnect OP2. • Turn starting switch ON.

Is voltage between OP2 (female) and chassis normal? YES

WF550-3 / WF550T-3

NO

20-255



2. Does not rotate in reverse direction Cause

Remedy

1 • 20 - 30 V • Disconnect SW1. • Turn starting switch ON.

Is voltage between SW1 (female) (2) and chassis normal?

NO

YES • • • •

Max 1 Ω Turn starting switch OFF. Switch (SW1) position: AUTO Disconnect SW1.

2 Is resistance between SW1 (male) (2) and (3) normal?

NO


Replace

Defective contact or disconnection in wiring harness between SLa (female) (2) and chassis ground

Repair or replace

Defective contact or disconnection in wiring harness between LSL (female) (5) and SLa (female) (1)

Repair or replace

Defective contact or disconnection in wiring harness between TM2 (female) (4) and LSL (female) (1)

Repair or replace

Defective contact or disconnection in wiring harness between SW1 (female) (3) and TM1 (female) (1), (7), (8)

Repair or replace

Defective contact or disconnection in wiring harness between TM1 (female) (3), (6) and TM2 (female) (1), (7)

Repair or replace

Defective relay (LSL)

Replace

YES 3 • • • •

20 - 30 V Disconnect SLa. Turn starting switch ON. Switch (SW1) position: AUTO

Is voltage between SLa (female) (1) and chassis normal?

NO

Voltage flows only during time of rotation in forward direction set as desired by timer (TM1). YES

4 • Max 1 Ω • Turn starting switch OFF. • Disconnect LSL and SLa.

Is resistance between LSL (female) (5) and SLa (female) (1) normal?

NO

YES 5 • Max 1 Ω • Turn starting switch OFF. • Disconnect TM2 and LSL.

Is resistance between TM2 (female) (4) and LSL (female) (1) normal?

NO

YES 6 • Max 1 Ω • Turn starting switch OFF. • Disconnect SW1 and TM1.

Is resistance between SW1 (female) (3) and TM1 (female) (1), (7), (8) normal?

NO

YES 7 • Max 1 Ω • Turn starting switch OFF. • Disconnect TM1 and TM2.

Is resistance between TM1 (female) (3), (6) and TM2 (female) (1), (7) normal?

NO

YES 8 • Replace with relay (LFL).

Does condition become normal when relay (LSL) is replaced?

NO

YES

Go to next page

20-256

Go to next page

WF550-3 / WF550T-3


From previous page


Cause

From previous page

Remedy



NO

YES


Replace


Replace


Replace


Repair or replace


Repair or replace

10 • Replace timer (TM1) with new part.


NO

YES



WF550-3 / WF550T-3

NO

20-257

EC-2


EC-2 Fan does not rotate (selector switch position: MANUAL) 1. Does not rotate in forward direction Cause

Remedy

Defective contact or disconnection in wiring harness between SW1 (female) (1) and SW2 (female) (2)

Repair or replace

NO


Replace

NO

Defective FORWARD / REVERSE selector switch

Replace

Defective contact or disconnection in wiring harness between SLb (female) (2) and chassis ground

Repair or replace

Defective contact or disconnection in wiring harness between LTM (female) (5) and SLb (female) (1)

Repair or replace


Repair or replace


Repair or replace

1 • 20 - 30 V • Disconnect SW1. • Turn starting switch ON.

Is voltage between SW1 (2) and chassis normal?

NO

YES 2 Is voltage between SW2 (female) (2) and chassis normal?

• 20 - 30 V • Disconnect SW2. • Turn starting switch ON.

NO

YES • Max 1 Ω • Turn starting switch OFF. • Switch (SW1) position: MANUAL • Disconnect SW1.

Is resistance between SW1 (male) (1) and (2) normal?

Max 1 Ω Turn starting switch OFF. Disconnect SW2. Switch (SW2) position: FORWARD


20 - 30 V Disconnect SLb. Turn starting switch ON. Switch (SW1) position: FORWARD (Wait for at least 15 seconds before measuring.)

Is voltage between SLb (female) (1) and chassis normal?

• • • •

• • • •

3

YES

4

YES

5 NO

YES 6

• Max 1 Ω • Turn starting switch OFF. • Disconnect LTM and SLb.

Is resistance between LTM (female) (5) and SLb (female) (1) normal?

NO

YES 7 • Max 1 Ω • Turn starting switch OFF. • Disconnect TM3 and LTM.

Is resistance between TM3 (female) (4) and LTM (female) (1) normal?

NO

YES 8 • Max 1 Ω • Turn starting switch OFF. • Disconnect TM3 and SW2.

Is resistance between TM3 (female) (1), (7) and SW2 (female) (3) normal?

NO

YES

Go to next page

20-258

Go to next page

WF550-3 / WF550T-3


From previous page

EC-2

Cause

From previous page

Remedy

9 • Replace with relay (LFL).


NO

YES


Replace


Replace


Replace


Repair or replace


Repair or replace



NO

YES



WF550-3 / WF550T-3

NO

20-259

EC-2


2. Does not rotate in reverse direction Cause

Remedy

1 Is voltage between SW1 (female) (2) and chassis normal?


NO

YES 2 Is voltage between SW2 (female) (2) and chassis normal?


NO

Defective contact or disconnection in wiring harness between SW1 (female) (1) and SW2 (female) (2)

YES • Max 1 Ω • Turn starting switch OFF. • Switch (SW1) position: MANUAL • Disconnect SW1.


• Max 1 Ω • Turn starting switch OFF. • Switch (SW2) operation: REVERSE • Disconnect SW2.


3 NO


Replace

NO


Replace

Defective contact or disconnection in wiring harness between SLa (female) (2) and chassis ground

Repair or replace

Defective contact or disconnection in wiring harness between LSL (female) (5) and SLa (female) (1)

Repair or replace

Defective contact or disconnection in wiring harness between TM2 (female) (4) and LSL (female) (1)

Repair or replace

Defective contact or disconnection in wiring harness between TM2 (female) (1), (7) and SW2 (female) (1)

Repair or replace

YES

4

YES

• 20 - 30 V • Disconnect SLa. • Turn starting switch ON. Switch position: REVERSE (Wait for at least 15 seconds before measuring.)

5 Is voltage between SLa (female) (1) and chassis normal?

NO

YES 6

• Max 1 Ω • Turn starting switch OFF. • Disconnect LSL and SLa.

Is resistance between LSL (female) (5) and SLa (female) (1) normal?

NO

YES 7 • Max 1 Ω • Turn starting switch OFF. • Disconnect TM2 and LSL.

Is resistance between TM2 (female) (4) and LSL (female) (1) normal?

NO

YES 8 • Max 1 Ω • Turn starting switch OFF. • Disconnect TM2 and SW2.

Is resistance between TM2 (female) (1), (7) and SW2 (female) (1) normal?

NO

YES

Go to next page

20-260

Go to next page

WF550-3 / WF550T-3


EC-2

Cause From previous page

Remedy

From previous page

9 • Replace with relay (LFL).


NO

YES


Replace


Replace


Replace


Repair or replace


Repair or replace



NO

YES



WF550-3 / WF550T-3

NO

20-261

EC-3


EC-3 Fan does not switch from forward to reverse rotation (selector switch position: AUTO) Cause

Remedy

1 • 20 - 30 V • Turn starting switch ON. • See Table 1 for reverse rotation time.

Is voltage between LSL (female) (1) and chassis normal?

NO

YES 2 Does condition become normal when relay (LSL) is replaced?

• Replace with relay (LFL).

NO

YES


Replace


Replace

Defective timer 2

Replace

Short circuit with power source in wiring harness between TM2 (female) (4) and LSL (female) (1)

Repair or replace

Defective timer 1

Replace

3 Does condition become normal when timer 2 is replaced?

• Replace with timer 3.

NO

YES

4 • Replace timer 1 with new part.

Does condition become normal when timer 1 is replaced? YES

NO

Table 1

REVERSE

FORWARD

FORWARD

REVERSE

Times set when shipping from factory •

Forward rotation time (ta): 2 hours

•

Reverse rotation time (tb): 2 minutes

•

No-load rotation time (tc): 15 seconds

20-262

WF550-3 / WF550T-3


EC-4

EC-4 Fan does not switch from forward to reverse rotation (selector switch position: MANUAL) Cause

Remedy

1 • See Table 1. • Turn starting switch OFF. • Operate FORWARD / REVERSE selector switch.

Is continuity of FORWARD / REVERSE selector switch normal?

NO


Replace


Replace


Replace

Short circuit with power source in wiring harness between TM2 (female) (4) and LSL (female) (1)

Repair or replace

Defective timer 2

Replace

YES 2

• Max. 1 V • Turn starting switch ON. • Approx. 15 seconds after operating FORWARD / REVERSE selector switch.

Is voltage between LTM (female) (1) and chassis normal?



NO

YES 3 NO

YES 4 Does condition become normal when timer 2 is replaced?


YES

NO

Table 1 (1)

(2)

(3)

Forward rotation Reverse rotation

WF550-3 / WF550T-3

20-263

EC-5


EC-5 Fan does not switch from reverse to forward rotation (selector switch position: AUTO) Cause

Remedy

1 • 20 - 30 V • Turn starting switch ON. • See Table 1 for forward rotation time.

Is voltage between LTM (female) (1) and chassis normal?

NO

YES 2 Does condition become normal when relay (LTM) is replaced?


NO

YES


Replace


Replace

Defective timer 3

Replace



NO

YES


• Replace timer 1 with new part.

YES

NO

Short circuit with power source in Repair or wiring harness between TM3 replace (female) (4) and LTM (female) (1) Defective timer 1

Replace

Table 1

REVERSE

FORWARD

FORWARD

REVERSE

Times set when shipping from factory •

Forward rotation time (ta): 2 hours

•

Reverse rotation time (tb): 2 minutes

•

No-load rotation time (tc): 15 seconds

20-264

WF550-3 / WF550T-3


EC-6

EC-6 Fan does not switch from reverse to forward rotation (selector switch position: MANUAL) Cause

Remedy

1 • See Table 1. • Turn starting switch OFF. • Operate FORWARD / REVERSE selector switch.

Is continuity of FORWARD / REVERSE selector switch normal?

NO


Replace


Replace


Replace

YES 2

• Max. 1 V • Turn starting switch ON. • Approx. 15 seconds after operating FORWARD / REVERSE selector switch.

Is voltage between LSL (female) (1) and chassis normal?



NO

YES 3 NO

YES 4 Does condition become normal when timer 3 is replaced?

Replace with timer 2.

YES

NO

Short circuit with power source in Repair or wiring harness between TM3 replace (female) (4) and LTM (female) (1) Defective timer 1

Replace

Table 1 (1)

(2)

(3)

Forward rotation Reverse rotation

WF550-3 / WF550T-3

20-265

EC-7


EC-7 When direction of fan is switched, it immediately switches 1. Forward → Reverse Cause

Remedy

1 • Replace with timer 3.

Does condition become normal when timer 2 is replaced?

NO

YES


Replace

Defective timer 2

Replace

2. Reverse → Forward Cause

Remedy

1 • Replace with timer 2.

Does condition become normal when timer 3 is replaced? YES

20-266

NO


Replace

Defective timer 3

Replace

WF550-3 / WF550T-3



WF550-3 / WF550T-3



WF550-3 / WF550T-3

TROUBLESHOOTING OF HYDRAULIC AND MECHANICAL SYSTEM (H MODE) H-1 Blade does not move . . . . . . . . . . . . . 20-302 H-2 Blade is slow or blade lacks power . . 20-303 H-3, H-4, H-5, H-6 . . . . . . . . . . . . . . . . . . . . H-3 – When blade is raised, it moves slowly at a certain height . . . . . . . . . . . . . . . . . . . . . H-4 – Blade cannot be pushed with lift cylinder (blade floats) . . . . . . . . . . . . . . . H-5 – Excessive hydraulic drift of blade . . . . H-6 – Blade shakes during operation . . . . . .

20-304 20-304 20-304 20-305 20-305

★ For the power train system, steering system, and brake system, see WA500-3, serial No. 50001 and up. ★ For details of the troubleshooting for all system in the hydraulic and mechanical system on the WF550-3, see the shop manual for the WA500-3, Serial No.: 50001 and up.

WF550-3 / WF550T-3

20-301

H-1 Blade does not move

TROUBLESHOOTING OF HYDRAULIC AND MECHANICAL SYSTEM (H MODE)

H-1 Blade does not move Ask the operator the following questions •

Did the problem suddenly start? Yes = Related equipment broken

•

Was there any abnormal noise when this happened? Where did the noise come from?

PPC valve b

c

d

Defective control lever linkage

Defective cylinder seal

Defective suction valve

Control valve

Cylinder

Others

e

f

Remedy

a

Defective actuation of load check valve

Defective PPC valve

Causes

: Replace : Repair : Addition : Clean

Defective actuation of blade spool

The following symbols are used to indicate the action to be taken when a cause of failure located.

No.

Problems

1

Does not move in both directions (RAISE and LOWER)

2

Does not move in one directions (RAISE and LOWER)

3 4

When blade relief pressure is measured

Oil pressure is low or there is no pressure in both directions (RAISE and LOWER) Oil pressure is low or there is no pressure in one directions (RAISE and LOWER)

5

When PPC valve output pressure is measured, oil pressure is found to be low or there is no pressure

6

When operating effort of blade control lever is measured, lever is found to be heavy

7

When travel of blade control lever is measured, it is found to be short

20-302

WF550-3 / WF550T-3


H-2 Blade is slow or blade lacks power

H-2 Blade is slow or blade lacks power Ask the operator the following questions •

Did the problem suddenly start? Yes = Related equipment broken

•

Was there any abnormal noise when this happened? Where did the noise come from?

•

Did the problem gradually appear? Yes = Wear of related parts, defective seal

PPC valve b

c

d

Defective control lever linkage

Defective cylinder seal

Defective suction valve

Control valve

Cylinder

Others

e

f

Remedy

a

Defective actuation of load check valve

Defective PPC valve

Causes

: Replace : Repair : Addition : Clean

Defective actuation of spool

The following symbols are used to indicate the action to be taken when a cause of failure located.

No.

Problems

1

Does not move in both directions (RAISE and LOWER)

2

Does not move in one directions (RAISE and LOWER)

3 4

When blade relief pressure is measured

Oil pressure is low in both directions (RAISE and LOWER) Oil pressure is low in one directions (RAISE and LOWER)

5

When PPC valve output pressure is measured, oil pressure is found to be low

6

When hydraulic drift of blade is measured, it is found to be exessive

7

When operating effort of blade control lever is measured, lever is found to be heavy

8

When travel of blade control lever is measured, it is found to be short

WF550-3 / WF550T-3

20-303

H-3, H-4, H-5, H-6


H-3, H-4, H-5, H-6 H-3 – When blade is raised, it moves slowly at a certain height Checks before troubleshooting •

Can any deformation be seen in the lift cylinder?

Cause •

Swelling or internal damage to lift cylinder tube

★ For other abnormalities when the blade is raised, go to "H-2 Blade is slow or blade lacks power."

H-4 – Blade cannot be pushed with lift cylinder (blade floats) See "H-2 Blade is slow or blade lacks power." Checks before troubleshooting •

Is the stroke of the lift spool in the main control valve properly adjusted?

Cause •

Defective seating of suction valve at lift cylinder bottom end of main control valve

•

Oil leakage from lift cylinder piston seal

20-304

WF550-3 / WF550T-3


H-3, H-4, H-5, H-6

H-5 – Excessive hydraulic drift of blade Ask the operator the following questions •

Did the problem suddenly start? Yes = Dirt caught in valve, broken part

•

Did the problem gradually appear? Yes = Worn parts

Checks before troubleshooting •

Is the lift spool at the neutral position? Yes = Seized link bushing, defect in spool detent

Troubleshooting and cause •

When measuring the hydraulic drift, is there any sound of oil leakage from inside the lift cylinder Yes = Defective cylinder packing

H-6 – Blade shakes during operation When digging or leveling operations are carried out with the blade control lever at HOLD, the blade and straight frame move up and down to follow the shape of the ground. Troubleshooting and Cause Measure the hydraulic drift of the blade and check if it is possible to lift the chassis with the lift cylinder. If the hydraulic drift of the lift cylinder is outside the standard value, go to "H-5 Excessive hydraulic drift of blade." 1. If the chassis cannot be raised with the lift cylinder, go to "H-4 Blade cannot be pushed with lift cylinder." 2. If the hydraulic drift of the blade is normal, operate the blade several times, and operate the lift cylinder to the end of it’s stroke. Is it now possible to raise the chassis with the lift cylinder? Yes = Vacuum had formed inside cylinder ★ However, if this problem appears frequently, the suction valve at the lift cylinder bottom end is defective.

WF550-3 / WF550T-3

20-305

H-3, H-4, H-5, H-6



20-306

WF550-3 / WF550T-3

30 DISASSEMBLY AND ASSEMBLY Special tool list . . . . . . . . . . . . . . . . . . . . . . . . 30-2 Sketches of special tools . . . . . . . . . . . . . . . 30-7 Starting motor assembly . . . . . . . . . . . . . . . 30-10 Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30-10 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . 30-10 Engine front seal . . . . . . . . . . . . . . . . . . . . . 30-11 Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30-11 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . 30-11 Radiator assembly . . . . . . . . . . . . . . . . . . . . 30-12 Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30-12 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . 30-13 Engine assembly . . . . . . . . . . . . . . . . . . . . . 30-14 Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30-14 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . 30-18 Front axle assembly . . . . . . . . . . . . . . . . . . . 30-19 Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30-19 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . 30-20 Front differential assembly . . . . . . . . . . . . . 30-21 Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30-21 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . 30-23 Rear axle assembly . . . . . . . . . . . . . . . . . . . 30-24 Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30-24 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . 30-29 Rear differential assembly . . . . . . . . . . . . . 30-30 Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30-30 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . 30-31 Differential gear assembly . . . . . . . . . . . . . 30-32 Disassembly . . . . . . . . . . . . . . . . . . . . . . . . . . 30-32 Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30-36

Installation (WF550-3) . . . . . . . . . . . . . . . . . . .30-59 Removal (WF550T-3) . . . . . . . . . . . . . . . . . . .30-59 Installation (WF550) . . . . . . . . . . . . . . . . . . . . .30-61 Disassembly . . . . . . . . . . . . . . . . . . . . . . . . . .30-62 Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30-66 Lift cylinder assembly . . . . . . . . . . . . . . . . . .30-70 Removal (WF550T-3) . . . . . . . . . . . . . . . . . . .30-70 Installation (WF550T-3) . . . . . . . . . . . . . . . . . .30-71 Boom, bucket and lift cylinders assembly .30-72 Disassembly . . . . . . . . . . . . . . . . . . . . . . . . . .30-72 Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30-74 Work equipment assembly . . . . . . . . . . . . . .30-77 Removal (WF550T-3) . . . . . . . . . . . . . . . . . . .30-77 Installation (WF550T-3) . . . . . . . . . . . . . . . . . .30-78 Engine hood assembly . . . . . . . . . . . . . . . . .30-79 Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30-79 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . .30-80 Floor frame assembly . . . . . . . . . . . . . . . . . .30-81 Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30-81 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . .30-84 Fuel tank assembly . . . . . . . . . . . . . . . . . . . .30-85 Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30-85 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . .30-85 Air conditioner condenser assembly . . . . . .30-86 Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30-86 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . .30-86 Reciver tank . . . . . . . . . . . . . . . . . . . . . . . . . .30-87 Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30-87 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . .30-87

Final drive assembly . . . . . . . . . . . . . . . . . . 30-44 Disassembly / assembly . . . . . . . . . . . . . . . . . 30-44 Steering cylinder assembly . . . . . . . . . . . . . 30-45 Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30-45 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . 30-46 Steering valve assembly . . . . . . . . . . . . . . . 30-47 Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30-47 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . 30-49

★ For details of disassembly and assembly of components not listed above, see the shop manual for the WA500-3, Serial No.: 50001 and up. (Removal and installation of the counterweight is not applicable.)

Slack adjuster assembly . . . . . . . . . . . . . . . 30-50 Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30-50 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . 30-50 Hydraulic tank assembly . . . . . . . . . . . . . . . 30-51 Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30-51 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . 30-53 PPC valve assembly . . . . . . . . . . . . . . . . . . 30-54 Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30-54 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . 30-55 Main control valve assembly . . . . . . . . . . . 30-56 Removal (WF550-3) . . . . . . . . . . . . . . . . . . . . 30-56

WF550-3 / WF550T-3

30-1

Special tool list

DISASSEMBLY AND ASSEMBLY

Special tool list ★ Tools with part number 79T-- cannot be supplied (they are items to be locally manufactured). ★ Necessity:

New/remodel:

n:........... Cannot be substituted, should always be installed (used) l:........... Extremely useful if available, can be substituted with commercially available part N:........... Tools with new part numbers, newly developed for this model R:........... Tools with upgraded part numbers, remodeled from items already available for other models Blank..... Tools already available for other models, used without any modification

★ Tools marked in the Sketch column are tools introduced in special sketches (See SKETCHES OF SPECIAL TOOLS).

Component

Symbol

Installation of engine cylinder head

Part No.

1

Part Name

795-521-1110

Push tool

2

790-101-5221

Grip

3

01010-51225

Bolt

4

01050-31640

Bolt

1

795-931-1210

Sleeve jig

2

795-931-1220

Sleeve jig

3

01050-31625

Bolt

4

01050-31645

Bolt

n n n n n n n n

790-102-1871

Wrench

n

1

790-201-2730

Spacer

2

791-520-4140

Screw

3

02215-11622

Nut

4

01643-32780

Washer

n n n n

5

790-101-2102

Puller (294.2 kN {30 ton})

n

6

790-101-1102

Pump

1

790-501-5200

Repair stand

2

790-901-2110

Bracket

3

793-310-2160

Plate

n n n n

1

799-301-1500

Oil leak tester

n

1

1

796-514-2000

Remover

n

1

2

796-515-2140

Adapter

n

1

3

1

B 2

Disassembly, assembly of transmission assembly

30-2

1

1

A

C

n

Wrench

Installation of engine front seal, rear seal

Disassembly, assembly of torque converter assembly

Q’ty

790-331-1110

2

Disassembly, assembly of PTO

Necessity

D 2

New/ remodel

Sketch

Nature of work, remarks Tightening of head assembly

1 1 1

Press fitting of front seal

3 1 1 3

Press fitting of rear seal

3 1

Removal, installation of round nut

1 1 2 2

Press fitting of PTO gear bearing inner race

1 1 1 1 1 Checking actuation of clutch piston Removal of No.3 planet gear shaft

WF550-3 / WF550T-3


Component

Symbol

Disassembly, assembly of transmission assemblyfonts

Special tool list

Part No.

Part Name

Necessity

Q’ty

n

1

New/ remodel

Sketch

Nature of work, remarks

790-201-1702

Push tool KIT

• 790-201-1741

• Push tool

1

• 790-101-5021

• Grip

1

• 01010-50816

• Bolt

1

790-101-2501

Push puller

• 790-101-2610

• Leg

2

• 790-101-2680

• Adapter

2

• 790-101-2510

• Block

1

• 790-101-2560

• Nut

2

01643-32060

Washer

n

2

790-101-2102

Puller (294kN {30ton})

n

1

790-101-1102

Pump

790-101-2501

Push puller

• 790-101-2540

• Washer

1

• 790-101-2620

• Leg

2

• 790-101-2510

• Block

1

• 790-101-2680

• Adapter

2

• 790-101-2560

• Nut

2

• 791-112-1180

• Nut

1

791-520-4140

Screw

793-615-1250

Adapter

790-201-2850

Spacer

01643-32060

Washer

n n n n

790-101-2102

Puller (294kN {30ton})

n

1

790-101-1102

Pump

n

1

6

793-615-1130

Spline inch

n

1

Adjusting preload of intermediate shaft bearing

7

796-751-1500

Wrench assembly

n

1

Adjusting preload of input shaft bearing

1

793T-615-1230

Push tool

2

793T-615-1240

Spacer

3

790-101-5421

Grip

4

01010-51240

Bolt

n n n n

1

790-452-1200

Pilot ring tool

n

1

Centering of body and upper cover

2

790-452-1100

Installer set

n

1

Press fitting of spacer

Press fitting of No.3, No.4 carrier bushing

3

4

n

n n

1

Pulling out of output shaft

1 1

D Disassembly, assembly of transfer assembly

5

8

Disassembly, assembly of Orbit-roll assembly fonts

1 1 1 2

1

N

1

N

1

Press fitting of dust seal and oil seal of output shaft

1

F

WF550-3 / WF550T-3

Press fitting of output shaft bearing

30-3

Special tool list


Component

Symbol

Removal, installation of differential assembly

Part No. 1

793-520-2510

2

793-520-2610

1

Part Name Bracket Plate

n

1

100V

1

220V, 240V

2

790-901-2110

Bracket

3

793-310-2160

Plate

1

793T-622-1120

Push tool

2

793T-622-1130

Spacer

3

790-101-5421

Grip

4

01010-51240

Bolt

1

792-525-1000

Micrometer

2

792-525-1230

Adapter

1

793T-622-1110

Plate

2

790-101-5421

Grip

3

01010-51240

Bolt

793T-622-1150

Fixture

n

1

793-520-1805

Brake tester

n

1

N

2

793-520-1851

Nipple

n

1

N

1

793-520-2680

Installer

2

791-580-1600

Push tool

3

• 791-580-1610

• Plate

1

4

• 791-580-1620

• Arm

4

5

• 791-580-1640

• Plate

1

6

• 791-580-1650

• Plate

4

7

• 01010-51425

• Bolt

8

8

• 01541-21670

• Nut

4

9

• 01640-21426

• Washer

4

10

792-530-1630

Stud

1

793-520-2680

Installer

n n

2

793-622-1200

Push tool

n

3

• 793-622-1210

4

7

n n

1 1 1

N

1

N

30-4

9

1

Press fitting of dust seal and oil seal of coupling cage

1 1

Adjusting preload of bearing

2 1

N

N

1 1 3

Press fitting of oil seal of outer drum Removal, installation of wheel hub Checking leakage of brake oil hub

1 1

Installation of floating seal (gear end)

8

Disassembly, assembly of brake assembly


1

Repair stand

6

Sketch

Removal, installation of differential assembly

790-501-5200

4

Disassembly, assembly of final drive assembly

1

n n n n n n n n n n n n n

3

H

n

New/ remodel

Repair stand

2

5

Q’ty

790-501-5000 1

Disassembly, assembly of differential assembly

Necessity

4 1 1

N

• Arm

4

N

• 793-622-1220

• Plate

1

N

5

• 791-580-1640

• Plate

1

6

• 792-530-1630

• Stud

4

7

• 01010-51425

• Bolt

4

8

• 01640-21426

• Washer

4

9

• 01580-01613

• Nut

4

Installation of floating seal (hub end)

Installation of floating seal (hub end)

WF550-3 / WF550T-3


Component

Symbol

Part No.

Necessity

n n n n

5

Sketch


2

793-520-2640

Push tool

3

793-520-2530

Guide

4

790-101-2300

Push puller

5

• 790-101-2310

• Block

1

6

• 02215-11622

• Nut

2

7

790-101-2102


8

790-101-1102

Pump

1

793-520-2550

Guide

2

01010-31480

Bolt

3

01643-31445

Washer

4

793-520-2640

Push tool

n n n n n

5

790-101-2102


n

1

6

790-101-1102

Pump

n

1

1

790-502-1003 or 790-502-2000

Repair stand

n

1

2

790-101-1102

Pump

n

1

2

790-330-1100

Wrench assembly

n

1

Removal, installation of cylinder head

3

790-302-1290

Socket (width across flats: 60 mm)

n

1

Removal, installation of nut

1

790-201-1500

Push tool KIT

n

1

Press fitting of dust seal

2

• 790-201-1580

• Plate

1

Steering cylinderust

3

• 790-201-1670

• Plate

1

Boom cylinder

4

• 790-201-1680

• Plate

1

Bucket cylinder

5

• 790-101-5021

• Grip

1

All cylindersr

6

• 01010-50816

• Bolt

1

All cylinders

1

790-201-1702

Push tool KIT

1

Press fitting of roll bushing

2

• 790-201-1771

• Push tool

1

Steering cylinder

3

• 790-201-1861

• Push tool

1

Boom cylinder

4

• 790-201-1871

• Push tool

1

Bucket cylinder

5

• 790-101-5021

• Grip

1

6

• 01010-50816

• Bolt

1

1

4

New/ remodel

Bar

n

K

U

Q’ty

793-520-2630

2

Disassembly, assembly of hydraulic cylinder assembly

Part Name

1

1

Removal, installation of center hinge

Special tool list

n

2 1 1 1

Press fitting of bearing of top center hinge portion

1 1 1 2 2 1

Press fitting of bearing of bottom center hinge portion

All cylinders

WF550-3 / WF550T-3

30-5

Special tool list


Component

Symbol

Disassembly, assembly of hydraulic cylinder assemblys

6

1 Disassembly, assembly of accumulator assembly

2

Part No.

Part Name

790-720-1000

Expander

2

796-720-1660

Ring

3

07281-01159

Clamp

4

796-720-1690

Ring

5

07281-02169

Clamp

6

796-720-1720

Ring

7

07281-02429

Clamp

1

790-102-2303

Wrench assembly

2

790-102-4300

Wrench assembly

3

790-102-4310

Pin

n n n n n n n n n

1

790-720-1000

Expander

n

2

796-720-1660

Ring

3

07281-01159

Clamp

n n

792-610-1700

Charging tool assembly

n

1

799-703-1200

Service tool KIT

2

799-703-1100

3

4

Vacuum pump 3

30-6

n

1

X

Charging air conditioner with gas

Necessity

799-703-1110

n n n

Q’ty 1 1 1

New/ remodel

Sketch

Nature of work, remarks Expansion of piston ring Steering cylinder

1 Boom cylinder 1 1 Bucket cylinder 1 1 1 1 1

Removal, installation of round head Expansion of piston ring

1 1 1

Charging with N2 gas

1 1

110V

1

220V

WF550-3 / WF550T-3


Sketches of special tools

Sketches of special tools NOTE Komatsu cannot accept any responsibility for special tools manufactured according to these sketches. H3-2

H6

WF550-3 / WF550T-3

30-7



H5-1

H3-1

30-8

WF550-3 / WF550T-3



D8-2

D8-1

WF550-3 / WF550T-3

30-9

Starting motor assembly


Starting motor assembly Removal

Disconnect the cable from the negative (–) terminal of the battery.

1. Remove ladder and handrail on left side of engine. 2. Remove left side cover (1).

3. Disconnect connector (2). 4. Disconnect wire (3) from magnet switch. 5. Remove 3 mounting bolts (4), then remove starting motor assembly (5). ★ The bottom mounting bolts of the starting motor are used to install the ground cable.

Installation Carry out installation in the reverse order to removal.

30-10

WF550-3 / WF550T-3


Engine front seal

Engine front seal Removal 1. Remove engine hood assembly. For details, see REMOVAL OF ENGINE HOOD ASSEMBLY. 2. Remove radiator assembly. For details, see REMOVAL OF RADIATOR ASSEMBLY. 3. Remove fan belt. 4. Remove mounting bolts (3), then remove crankshaft pulley (4). 1 ★ Be careful not to damage the damper when removing. If the damper is damaged, it will lead to failure of the engine.

2

5. Remove front seal (5).

Installation Carry out installation in the reverse order to removal. 1 ★ Align the crankshaft and crankshaft pulley with a pin (round tube).

t Crankshaft pulley mounting bolt: 279.3 ± 34.3 Nm {28.5 ± 3.5 kgm} 2 r Lip of oil seal: Grease (G2-LI) ★ Press fit the front seal to a point 13 face of the front cover.

+1 0

mm from the end

★ Use tool A2 when press fitting.

WF550-3 / WF550T-3

30-11

Radiator assembly


Radiator assembly Removal 1. Remove engine hood assembly. For details, see REMOVAL OF ENGINE HOOD ASSEMBLY. 2. Loosen drain valve (1) and drain coolant.

3. Disconnect aeration hose (2) and return hose (3). 4. Disconnect make-up line hose (4).

5. Disconnect radiator outlet hose (6). 6. Disconnect torque converter cooler outlet and inlet hoses (7). 7. Disconnect hydraulic cooler outlet and inlet hoses (8).

8. Disconnect 2 hoses for fan motor drive at front of radiator. 9. Remove cover (9) at front bottom of radiator. 10. Loosen radiator mount bolt (10).

30-12

WF550-3 / WF550T-3


Radiator assembly

11. Sling radiator assembly (11) and remove bolt (10).

12. Lift off radiator assembly. ★ When lifting off the radiator assembly, move it to the rear while raising it.

Radiator assembly: 400 kg

Installation •

Carry out installation in the reverse order to removal.

•

Refilling with water Tighten radiator drain valve and add water through water filler to the specified level. Run the engine to circulate the water through the system. Then check the water level again.

WF550-3 / WF550T-3

30-13

Engine assembly


Engine assembly Removal

Stop the machine on level ground and install the safety bar on the frame. Then lower the bucket to the ground, stop the engine, and put blocks under the steel wheels to prevent the machine from moving.

★ Disconnect the cable from the negative (-) terminal of the battery.

1. Loosen drain valve (1) and drain coolant. 2. Remove engine hood assembly. For details, see REMOVAL OF ENGINE HOOD ASSEMBLY. 3. Remove radiator assembly. For details, see REMOVAL OF RADIATOR ASSEMBLY. 4. Remove bulkhead assembly. For details, see REMOVAL OF BULKHEAD ASSEMBLY.

Engine flywheel end 5. Remove switch and PPC pump (2). 6. Disconnect output shaft lubrication tubes (3).

7. Disconnect drive shaft (4).

30-14

1

WF550-3 / WF550T-3


Engine assembly

Engine oil cooler end 8. Disconnect water temperature sensor connector (5) (E05). 9. Disconnect air cleaner sensor wires (6) (E19 and E20). 10. Remove clamps (7).

11. Disconnect alternator wires (8) (E15, E16, and E17). 12. Disconnect fusible link wires (9) (E01 and E02). 13. Remove clamp (10).

14. Disconnect magnet switch connector (11) (E13). 15. Disconnect water temperature sensor connector (12) (E06). 16. Remove clamp (13). 17. Disconnect wire (14). 18. Remove ground connection (15) (E14). ★ This is tightened with the mounting bolt of the starting motor.

19. Disconnect heater hoses (16) and (17). ★ Return hose (17) is connected to the bottom of the water pump inlet connector.

Engine injection pump end 20. Disconnect connector (18) (E12). 21. Disconnect air conditioner compressor hoses (19). ★ Collect the freon gas.

WF550-3 / WF550T-3

30-15

Engine assembly


22. Disconnect fuel hoses (20) and (21).

23. Disconnect fuel return hose (22). 24. Disconnect engine oil level sensor connector (23). 25. Remove clamp (24).

26. Disconnect throttle wire (25) at pump end (26) and adjustment end (27). 27. Disconnect engine oil pressure sensor harness (28) (E11).

28. Disconnect engine speed sensor connector (29) (E04). 29. Disconnect connector (30) (E03) for engine stop motor.

30-16

WF550-3 / WF550T-3


Engine assembly

30. Disconnect heater switch wires (31) (E08 and E09). 31. Remove clamps (32), (33), and (34). 32. Remove mounting bolts (36) of engine oil drain valve (35), and push to fuel tank end.

33. Sling engine assembly, and remove front mount bolt (36) and rear mount bolt (37). 2

Front

Rear

34. Lift off engine assembly (38). ★ When lifting off the engine assembly, move it slowly to the rear of the machine while raising it. ★ Be careful that there is no interference.

Engine: 1,700 kg

WF550-3 / WF550T-3

30-17

Engine assembly


Installation Carry out installation in the reverse order to removal. 1 t Drive shaft mounting bolt: 110.7 ± 12.7 Nm {11.3 ± 1.3 kgm}

Center of machine Clearance a

★ Wipe the mating surface with a clean cloth before connecting.

2 t Mount bolt: 744.8 ± 83.3 Nm {76.0 ± 8.5 kgm} ★ Tighten the mounting bolts fully so that between the engine damper and the front support is clearance a. Clearance a: 5 mm

Refilling with water Tighten radiator drain valve and add water through water filler to the specified level. Run the engine to circulate the water through the system. Then check the water level again.

30-18

WF550-3 / WF550T-3


Front axle assembly

Front axle assembly Removal

Stop the machine on level ground, install the safety bar on the frame, and put blocks under the steel wheels to prevent the machine from moving. 1. Insert block between top face (1) of left and right rear axle housings and frame (2). 2. Start engine, operate work equipment to raise front axle, then set block ô under front frame on left and right sides and operate work equipment to lower frame. ★ Check that the front steel wheels can be removed, then lower the work equipment to the ground.

3. Sling left and right steel wheels (3), remove hub nuts, then lift off. 1 ★ Fit shackles at 2 places to the steel wheel, then use a lever block to remove.

Steel wheel (Reference value): 1,660 kg (WF550) 2,020 kg (WF550T)

4. Using garage jack, remove front undercover. 5. Disconnect front drive shaft (4) at differential end.

2

★ Make counter marks to act as a guide when assembling.

WF550-3 / WF550T-3

30-19

Front axle assembly


6. Disconnect brake tube (5) from slack adjuster. 7. Remove brake tubes (6) and (7). ★ After disconnecting the piping, fit blind plugs.

8. Sling one side of front axle assembly (8) and set garage jack to other side. 9. Remove mounting bolts (9).

3

10. Operate crane and garage jack to lower axle assembly. ★ Be careful not to let the slack adjuster on top of the axle housing hit the frame.

Front axle assembly: 2,350 kg 11. Pull out front axle assembly from chassis.

Installation Carry out installation in the reverse order to removal. 1 t Hub nut: 470.4 ± 49.0 Nm {48.0 ± 5.0 kgm} 2 t Drive shaft mounting bolt: 110.7 ± 12.7 Nm {11.3 ± 1.3 kgm} 3 t Axle mounting bolt: 2744.0 ± 294.0 Nm {280.8 ± 30.0 kgm}

30-20

WF550-3 / WF550T-3



Front differential assembly Removal

Stop the machine on level ground, install the safety bar on the frame, and put blocks under the steel wheels to prevent the machine from moving.

1. Remove drain plugs (1) and (2), and drain oil.

1

Axle oil: 95 l

2. Operate work equipment to raise front axle, then set stand under left side of axle. 3. Sling left steel wheel (3), then remove hub nut and lift off. 2 ★ Fit shackles at 2 places to the steel wheel, then use a lever block to remove.

Steel wheel (Reference value): 1,660 kg (WF550) 2,020 kg (WF550T) 4. Remove left and right final drive covers (4).

WF550-3 / WF550T-3

30-21



5. Using forcing screws , pull out drive shaft (5) approx. 200 mm together with sun gear (6). 6. Using garage jack, remove front undercover.

7. Remove front drive shaft (7). ★

Sling the drive shaft and lower it slowly.

8. Remove 2 mounting bolts of differential (8), and install guide bolt . ★

Screw in the guide bolt fully and check that all the threads have entered the hole.

★

First, screw in the guide bolt, then remove the remaining mounting bolts.

to front frame (9), and set so that differen9. Set lever block tial assembly does not fall over. 10. Pull out differential (8) approx. 20 mm from axle housing (10) along guide bolts. ★

Be careful not to damage the O-ring.

11. Install tools H1-1 and H1-2 to garage jack, and insert between differential and axle housing, then install differential to tool H1-1.

4

12. Adjust lever block and height of jack, and remove differential assembly slowly.

30-22

Differential assembly: 330 kg

WF550-3 / WF550T-3



13. Operate jack and pull out differential assembly (8) to outside of chassis. 14. Remove O-ring (11).

Installation Carry out installation in the reverse order to removal. 1 t Drain plug: 151.9 ± 24.5 Nm {15.5 ± 2.5 kgm} 2 t Hub nut: 470.4 ± 49.0 Nm {48.0 ± 5.0 kgm} 3 t Drive shaft mounting bolt: 110.7 ± 12.7 Nm {11.3 ± 1.3 kgm} 4 t Differential mounting bolt: 548.8 ± 58.8 Nm {56.0 ± 6.0 kgm} Refilling with oil (axle) Add oil through the oil filler to the specified level.

WF550-3 / WF550T-3

30-23

Rear axle assembly


Rear axle assembly Removal

Stop the machine on level ground, install the safety bar on the frame, and put blocks under the steel wheels to prevent the machine from moving. 1. Jack up chassis, set block under rear frame, and support bottom of bumper with stand ô.

2. Sling left and right steel wheels (1), then remove hub nut and lift off. 1 ★ Fit shackles at 2 places to the steel wheel, then use a lever block to remove.

Steel wheel (Reference value): 2,080 kg 3. Using garage jack, remove front undercover.

4. Disconnect rear drive shaft (2) from rear axle.

2

Rear drive shaft: 37 kg

30-24

WF550-3 / WF550T-3


Rear axle assembly

5. Disconnect hose (3) between brake pedal and slack adjuster at slack adjuster end. 6. Disconnect tubes (4) and (5) between slack adjuster and left and right wheel brakes. ★ Always remove the brake tube before removing the axle. There is danger that it may be crushed.

7. Disconnect grease tubes (6) and (7) from axle support at rear end.

8. Disconnect grease tube (8) from axle support at front end. ★ Remove the clamps of the brake hose from the support.

9. Secure axle support and rear axle with chain. 10. Remove mounting bolts, then using garage jack to maintain balance, lower axle assembly. 3

Rear axle assembly: 2,200 kg

WF550-3 / WF550T-3

30-25

Rear axle assembly


11. Pull out rear axle assembly (9) from chassis. ★ Support both ends of the axle with jacks.

12. Remove front support (10) from rear axle.

4

★ Be careful not to damage the packing.

Front support: 95 kg

13. Remove packings (11) and (12) from front support.

14. Remove bushing (13) from front support. ★ Remove all dirt and oil from the bushing mounting surface inside the front support.

30-26

WF550-3 / WF550T-3


15. Sling rear support, and remove thrust cap (14).

Rear axle assembly

5

16. Remove thrust washer (15), thrust plate (16), and thrust washer (17) from rear axle. 6

17. Lift off rear support (18).

Rear support: 115 kg

WF550-3 / WF550T-3

30-27

Rear axle assembly


18. Remove packing (19) from rear support.

19. Remove bushing (20) from rear support. ★ Remove all dirt and oil from the bushing mounting surface inside the rear support.

30-28

WF550-3 / WF550T-3


Rear axle assembly

Installation Carry out installation in the reverse order to removal. 1 t Hub nut: 471 ± 49 Nm {48 ± 5 kgm} 2 t Drive shaft mounting bolt: 110.7 ± 12.7 Nm {11.3 ± 1.3 kgm} 3 t Rear support mounting bolt: 1,568 ± 196 Nm {160.0 ± 20.0 kgm} ★ Soak a cloth with primer for Loctite prism adhesive, then wipe the adhesion surface at the bushing end.

r Adhesion surface at rear support end: Instant adhesive Loctite Prism 411 (approx. 3g) ★ Install the bushing within 5 minutes of coating it with primer. ★ Do not mix the primer with adhesive when using it. ★ Be careful to install the packing with the lip facing in the correct direction.

r Lip of packing: Grease (G2-LI) r Rear axle mount portion: Grease (G2-LI) 4 t Front support mounting bolt: 1,568 ± 196 Nm {160.0 ± 20.0 kgm} ★ Coat the bushing in the same way as for the rear axle.

r Lip of packing: Grease (G2-LI) r Front axle mount portion: Grease (G2-LI) 5 t Thrust cap mounting bolt: 279.3 ± 29.4 Nm {28.5 ± 3.0 kgm} 6 t Thrust plate mounting bolt: 279.3 ± 29.4 Nm {28.5 ± 3.0 kgm}

WF550-3 / WF550T-3

30-29



Rear differential assembly Removal


1. Remove rear axle assembly from chassis. For details, see REMOVAL OF REAR AXLE ASSEMBLY. ★ Do not remove the rear support from the rear axle.

Rear support

Rear axle

2. Remove plug (1) and drain axle oil. ★ Set so that the drain plug is at the bottom. Axle oil: 95 l

3. Remove cover (2).

4. Using forcing screws, pull out drive shaft (3). ★ Pull the drive shaft out approx. 200 mm.

30-30

WF550-3 / WF550T-3


5. Using eyebolts, lift off rear differential assembly (4).


1

Rear differential assembly: 330 kg ★ Remove the O-ring from the housing mating surface.

Installation Carry out installation in the reverse order to removal. 1 r Differential mounting bolt: Thread tightener (LT-2) t Differential mounting bolt: 548.8 ± 58.8 Nm {56.0 ±6.0 kgm} ★ Adjusting shims on shaft Adjust the shims on the shaft if the differential assembly or axle housing have been replaced.

a. Tighten mounting bolts of shaft (5) uniformly, then measure clearance a between axle housing and shaft. (Do not assemble the shims. Tighten the mounting bolts to 3.9 ± 0.1 Nm {0.4 ± 0.1 kgm}.)

Axle housine

b. Add 0.1 ± 0.05 mm to the measurement for clearance a, then select a shim within that range and assemble it. •

Shim thickness: Clearance a + (0.1 ± 0.05 mm)

t Mounting bolt: 112.7 ± 9.8 Nm {11.5 ± 1.0 kgm}

WF550-3 / WF550T-3

30-31

Differential gear assembly


Differential gear assembly Disassembly

4

1. Set differential assembly (1) on special tool H2.

Differential assembly: 330 kg

2. Differential gear case assembly a. Remove left and right locks (6), and with a bar, turn nut (7) until it become loose.

b. Remove mounting bolts (9) of cap (8). ★

Check the counter marks on the left and right bearing caps. If the counter marks are not clear, make new counter marks.

c.

Remove nut and lift out differential gear case assembly (10).

4

Differential gear assembly: 170 kg

3. Pinion assembly a. Turn over differential assembly.

Front side

Rear side

b. Remove coupling (28). c.

30-32

Remove case (2).

WF550-3 / WF550T-3



d. Remove oil seal (3) and dust seal (3A) from case. Rear side

Front side

e. Screw in forcing screw (Thread dia. = 18 mm, Pitch = 1.75 mm), and fit out pinion assembly (4). ★ Check number of shims (5).

Fine disassembly of pinion assembly 4. Bearing, collar, cage a. Support cage (11), push shaft with press and tack out pinion.

b. Remove bearing (12) and collar from cage.

WF550-3 / WF550T-3

30-33


c.


Remove outer races (13) and (14) from cage (11).

5. Pinion, bearing a. Remove snap ring (15), then remove bearing (16). b. Remove bearing (17).

30-34

WF550-3 / WF550T-3



Disassembly of differential gear assembly

6. Cover a. Remove bearing (18). b. Remove mounting bolts (19), then remove cover (20). c.

Remove thrust washer (21), plate (22), disc (23), pressure ring (24), and side gear (25).

d. Remove assembly of pinion gear (29) and shaft (27) from case (26), then remove pinion gear from shaft. 7. Bevel gear, case a. Remove bearing (30). b. Remove mounting bolts, then disconnect bevel gear (31) and case (26).

WF550-3 / WF550T-3

30-35



Assembly ★ When replacing the pinion or bevel gear, always replace as a set. Be careful not to mix the sets. Replace the case and cover also as a set.

Assembly of differential gear assembly 1. Ring gear a. Press fit bearing (30) to case (26). b. Install bevel gear (31) to case (26). r Mounting bolt: Thread tightener (LT-2) t Mounting bolt: 490 – 608 Nm {50 – 62 kgm}

2. Side gear, disc, plate (bottom) a. Install thrust washer (21-1) to case (26). ★ Insert the washer securely inside the case.

r Thrust washer: Coat both surfaces with grease (G2-LI) b. Install 2 each of plate (22-1) and disc (23-1) in order. ★

Use a 3.8t plate (425-22-27460). (Both plates)

r Disc: Coat both surfaces with Shell DONAX TD. c.

Install pressure ring (24-1) and assemble side gear (25-1).

3. Pinion gear Install pinion gear (29) to shaft (27), and assemble to case. ★ When assembling the shaft, fit the central grooves in turn. ★ Insert the corner of the shaft securely in the groove of the pressure ring.

30-36

WF550-3 / WF550T-3



4. Side gear, disc, plate (top) a. Assemble side gear (25) and pressure ring (24) inside case. ★ Insert the corner of the shaft securely in the groove of the pressure ring. ★ Rotate the side gear 2 – 3 times backwards and forwards to settle it.

b. Install 2 each of disc (23) and plate (32) in order. ★ Use a 3.8t plate (425-22-27460). (Both plates)

r Disc: Coat both surfaces with Shell DONAX TD. 5. Adjustment a. Adjusting clearance of disc and plate Measure dimension A from top surface of case to plate and dimension B from cover mounting surface to faucet joint portion, and calculate clearance between plates. Clearance between plates (discs): A – B = 0.2 – 0.8 mm ★ If the clearance is not within the standard range, use a 3.7t plate (425-22-27450) or 3.9t plate (425-22-27470) to ensure the proper clearance. The difference between the total thickness of the 2 plates used at the top and bottom should be within 0.1mm.

6. Cover a. Press fit bearing (18) to cover (20). b. Install thrust washer (21) to cover (20). ★ Insert the washer securely inside the cover.

r Thrust washer: Coat both surfaces with grease (G2-LI) c.

Install cover (20) and tighten with bolt (19). r Mounting bolt: Thread tightener (LT-2) t Mounting bolt: 115 – 122 Nm {11.7 – 12.4 kgm} ★ Align counter marks a of the case and cover.

WF550-3 / WF550T-3

30-37



7. Measurement of differential torque Lock (prevent from rotating) side gear at ring gear side of differential assembly, then measure rotating force of side gear on opposite side. •

Differential torque: Max. 15 Nm {1.5 kgm}

★ Except for the side gear, rotate the differential freely. ★ Any measurement tool can be used that satisfies the measurement conditions and can hold the side gear in position.

Fine assembly of pinion assembly 8. Bearing a. Using press fit kit ÷ (26 mm inner diameter). Install pinion bearing (17). b. Using press fit kit û (55 mm inner diameter), install bearing (16). r Rotating surface of bearing: Engine oil (EO30-CD)

c.

30-38

Install snap ring (15).

WF550-3 / WF550T-3



9. Cage a. Install outer races (14) and (13). b. Install cage (11) to pinion assembly.

10. Collar Install collar (27). 11. Bearing Using press fit kit ÷ (76 mm inner diameter), install bearing (12).

Assembly of differential assembly ★ Set differential case on special tool H2.

12. Pinion assembly a. Assemble shims (5) removed when disassembled. ★ Standard shims thickness: 2.1 mm.

b. Using eye-bolts û (Thread dia. = 12 mm, Pitch = 1.75 mm), install pinion assembly (4).

c.

Remove oil seal (3) and dust seal (3A) to case. r Lip of oil seal: Grease (G2-LI)

Front side

Rear side

r Lip of dust seal: Grease (G2-LI)

WF550-3 / WF550T-3

30-39



d. Fit O-ring to case, and install case (2). Front side

Rear side

t Mounting bolt: 279.3 ± 29.4 Nm {28.5 ± 3.0 kgm} r Mounting bolt: Tread tightener (LT-2) e. Insert coupling (28), fit O-ring and tighten holder. r Mounting bolt: Thread tightener (LT-2) t Mounting bolt: 921 ± 98 Nm {94 ± 10 kgm} ★ Fit the balancer to bolt hole of coupling, and measure the rotating torque. ★ Rotating torque: Max. 50.0 N {5.1 kg}

13. Differential gear assembly Sling differential gear assembly (10) and install case.

14. Nut, cap a. Align nut (7) with differential case groove and install.

b. Install cap (8) and tighten (9). r Mounting bolt: Thread tigntener (LT-2) t Mounting bolt: 931 ± 98 Nm {95 ± 10 kgm} ★ Check match marks on bearing cup before installing. ★ Rotate bevel gear 20 – 30 times to settle in, then tighten bolt.

30-40

WF550-3 / WF550T-3



★ Bearing pre-load adjustment steps are as follows.

I.

Install tool H4-1 and H-2 to cap on both sides.

II. Measure clearance “a” between tool H4-2 with tool H4-1.

III. Add 0.26 ± 0.07 mm to measurement dimension and set scale on tool H4-1. ★ The added dimension becomes the amount of bending of the case, given before pre-load and given after pre-load.

IV. Tighten adjusting nut with bar until increased amount becomes 0.26 ± 0.07 mm. ★ Caution for pre-load adjustment When adjusting nut is overtightened, in case the amount of increased bending surpasses the standard measurement, return adjusting nut to position before adjusting. Then while rotating bevel gear, lightly tap bearing cap and bevel gear with plastic hammer, and check that there is no clearance in position b.

WF550-3 / WF550T-3

No clearance

30-41



15. Adjusting tooth contact, backlash Adjust the backlash, and at the same time adjust tooth contact. a. Adjust backlash as follows: I.

Movement of bevel gear is done with adjusting nut (7). At this time, so as not to change pre-load pressurization of bearing, turn nuts on both sides, the same amount each, in same direction.

II. Put dial gauge í in vertical contact with forward and reverse sides of outer edge of bevel gear tooth face, and while turning adjusting nut, adjust until gauge meter fluctuation becomes 0.3 – 0.4 mm. ★ Measure at 3 or 4 places, and keep the pinion gear fixed when measuring.

b. Adjust tooth contact as follows: I.

Mix red lead (minium) with oil, then coat the tooth face of 7 or 8 teeth of the bevel gear.

II. Rotate the pinion gear forward and in reverse and check the tooth contact. III. Adjusting tooth contact Coat face 7 or 8 teeth of bevel gear lightly with red lead (minimum). Hold the bevel gear by hand to act as a brake, rotate the pinion gear forward and backward and inspect the pattern left on the teeth.

Tooth contact

30-42

Cause

Procedure for adjustment

The tooth contact pattern should start from about 5 mm from the toe of the bevel gear and cover about 50% of the length of the tooth. It should be in the center of the tooth height.

When adjusting the pinion gear, change the thickness of the shims between the differential case and the bearing cage. Adjust the bevel gear in the same way as when adjusting the backlash.

Pinion gear is too far from bevel gear.

1. Reduce shims at pinion gear to bring closer to bevel gear. 2. Move bevel gear further away from pinion gear and adjust backlash correctly.

WF550-3 / WF550T-3


Tooth contact


Cause

Procedure for adjustment

Pinion gear is too close to bevel gear.

1. Increase shims at pinion gear to move away from bevel gear. 2. Move bevel gear colser to pinion gear and adjust backlash correctly.

Bevel gear is too close to pinion gear.

1. Reduce shims at pinion gear to bring closer to bevel gear. 2. Move bevel gear further away from pinion gear and adjust backlash correctly.

Bevel gear is too far from pinion gear.

1. Increase shims at pinion gear to move away from bevel gear. 2. Move bevel gear closer to pinion gear and adjust backlash correctly.

★ When adjusting the driven gear, do not change the pre-load of the bearing. Tnrn the left and right adjusting nut, the same amount each (check by the number of notches), in the same direction.

16. Lock After adjusting tooth contact and backlash, install lock (6). r Mounting bolt: Thread tightener (LT-2) t Mounting bolt: 27.5 – 34.3 mm {2.8 – 3.5 kgm}

WF550-3 / WF550T-3

30-43

Final drive assembly


Final drive assembly Disassembly / assembly ★ The axle oil capacity is different from the WA500-3, Serial No.: 50001 and up. For details of the procedure, see the WA500-3 shop manual. Axile oil: 95 l

30-44

WF550-3 / WF550T-3


Steering cylinder assembly

Steering cylinder assembly Removal


Safety bar

1. Remove bolts (1), loosen bolt (2), then rotate cover (3) carefully towards rear of machine. ★ Rotate the cover using bolt (2) as the fulcrum. ★ The operating space is confined, so be extremely careful when carrying out the operation.

•

There is no inspection cover (3) on the WF550T-3, so carry out the bottom removal and installation work from the center of the chassis.

2. Disconnect bottom hose (4). 3. Disconnect grease tube (5). 4. Remove mounting bolt (6), then pull out pin (7). ★ Note the number and thickness of the shims to use as a guideline when assembling.

WF550-3 / WF550T-3

30-45

Steering cylinder assembly


5. Disconnect head hose (8).

6. Remove mounting bolt (9), then pull out pin (10). ★ Note the number and thickness of the shims to use as a guideline when assembling.

7. Using lever block, lift off steering cylinder (11). ★ Carry out the removal operation for the cylinder using two workers. ★ Be careful not to damage the cylinder rod.

Steering cylinder: 47 kg

Installation Carry out installation in the reverse order to removal. NOTE When aligning the position of the pin hole, use a bar. Never insert your fingers in the pin hole.

Bottom end

Rod end

★ Adjust the shims so that the clearance is specified value. Clearance a + b = Less than 1.0 mm (The specified value is the same for both the rod end and the bottom end).

30-46

WF550-3 / WF550T-3


Steering valve assembly

Steering valve assembly Removal

Stop the machine on level ground and turn the steering fully to the right. Then stop the engine and put blocks under the steel wheels to prevent the machine from moving.

There is no cut-off valve installed to the WF550T-3, so exclude the procedure for the cut-off valve and carry out the remaining procedures in the order given. 1. Remove bolt (1), loosen bolt (2), then rotate cover (3) carefully towards rear of machine. ★ Rotate the cover using bolt (2) as the fulcrum. ★ The operating space is confined, so be extremely careful when carrying out the operation.

•

There is no inspection cover (3) on the WF550T-3, so this work does not apply.

2. Remove side cover (4).

3. Remove mounting bolts (5), and disconnect bracket (6). 4. Remove mounting bolts (7), and disconnect bracket (8).

WF550-3 / WF550T-3

30-47



5. Disconnect hose (9) between cut-off valve and steering valve. 6. Disconnect hose (10) between cut-off valve and loader circuit. 7. Disconnect hoses (11), (12) between hydraulic tank and cutoff valve. ★ Hose (12) is at the rear of the cut-off valve.

8. Disconnect tubes (13) between steering valve and steering cylinder. 9. Disconnect tube (14) between steering valve and hydraulic tank.

10. Disconnect hose (15) between stop valve and steering valve. 11. Disconnect hose (16) between stop valve and steering valve. ★ It is connected to both ends of the steering valve.

12. Disconnect hose (17) between steering valve and steering pump. 13. Disconnect tube (18) between switch pump and steering valve. 14. Disconnect hose (19) between steering valve and cut-off valve. 15. Remove mounting bolt (20).

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WF550-3 / WF550T-3



16. Using guide bolt , pull out steering valve assembly (21) together with bracket approx. 200 mm to center of machine. ★ Remove the cut-off valve at this point.

1

17. Lift off steering valve assembly (21) together with bracket.

Installation Carry out installation in the reverse order to removal. 1 ★ Install the cut-off valve after lowering the steering valve assembly together with the bracket to the mounting position. ★ After installing the cut-off valve, use the guide bolt to move close to the frame and install.

WF550-3 / WF550T-3

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Slack adjuster assembly


Slack adjuster assembly Removal

Stop the machine on level ground and put blocks under the steel wheels to prevent the machine from moving.

1. Remove cover (1) on top of front frame.

2. Disconnect tube (2) between brake valve and slack adjuster. 1 3. Disconnect tube (3) between slack adjuster and left and right brake pistons. 2 4. Remove mounting bolts, then remove slack adjuster (4). ★ The operating space is confined, so be extremely careful when carrying out the operation.

Installation Carry out installation in the reverse order to removal. 1 t Tube: 80.9 ± 12.3 Nm {8.3 ± 1.3 kgm} 2 t Tube: 68.6 ± 9.8 Nm {7.0 ± 1.0 kgm}

30-50

WF550-3 / WF550T-3


Hydraulic tank assembly

Hydraulic tank assembly Removal

• Stop the machine on level ground, install the safety bar on the frame, and put blocks under the steel wheels to prevent the machine from moving. • Loosen the oil filler cap slowly to release the pressure inside the hydraulic tank. Then operate the steering wheel and control levers several times to release the remaining pressure in the hydraulic piping. 1. Remove cover (1). 2. Loosen plug (2) on top of the hydraulic tank filter and bleed the air from tank. 1

3. Remove plug (3), then loosen valve (4) and drain hydraulic oil. Hydraulic oil: 175 l

4. Remove guard (5) and ladder floor (14).

Ladder floor: 35 kg

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5. Disconnect main suction tube (6). 6. Disconnect return tube (7) from cooler. 7. Disconnect main return tube (8).

8. Disconnect hose (9) between brake valve and hydraulic tank. 9. Disconnect stop valve, charge valve, PPC, Orbit-roll, and drain hoses (10).

10. Sling hydraulic tank, then remove mounting bolts (11) and (12). 2

11. Lift off hydraulic tank assembly (13).

Hydraulic tank assembly: 300 kg

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WF550-3 / WF550T-3



Installation Carry out installation in the reverse order to removal. 1 t Plug: 11.8 ± 1.0 Nm {1.2 ± 0.1 kgm} 2 t Hydraulic tank bolt: 277.3 ± 32.3 Nm {28.3 ± 3.3 kgm}

WF550-3 / WF550T-3

30-53

PPC valve assembly


PPC valve assembly Removal

• Stop the machine on level ground, install the safety bar on the frame, and put blocks under the steel wheels to prevent the machine from moving. • Loosen the oil filler cap slowly to release the pressure inside the hydraulic tank. Then operate the steering wheel and control levers several times to release the remaining pressure in the hydraulic piping. 1. Open cover (1). 2. Loosen plug (2) on top of the hydraulic tank filter and bleed the air from tank. 1

3. Remove console box cover (3) on right side of operator’s seat. 4. Disconnect rods (4).

5. Disconnection of hoses from PPC valve a. Disconnect hoses P1 (8) and P4 (6) for bucket control •

There is no P1 or P4 circuit on the WF 550T-3, so install a blind plug.

b. Disconnect hoses P3 (7) and P2 (5) for boom control c.

Disconnect hose (9) from PPC pump

d. Remove eyebolt (10) of return hose leading to hydraulic tank. ★ After disconnecting the hoses, fit tags to distinguish them.

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WF550-3 / WF550T-3


PPC valve assembly

6. Remove mounting bolts (11), then remove PPC valve assembly (12).

Installation Carry out installation in the reverse order to removal. 1 t Plug: 11.8 ± 1.0 Nm {1.2 ± 0.1 kgm}

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Main control valve assembly


Main control valve assembly Removal (WF550-3)

• Stop the machine on level ground, install the safety bar on the frame, and put blocks under the steel wheels to prevent the machine from moving. • Loosen the oil filler cap slowly to release the pressure inside the hydraulic tank. Then operate the steering wheel and control levers several times to release the remaining pressure in the hydraulic piping. 1. Open cover (1). 2. Loosen plug (2) on top of the hydraulic tank filter and bleed air from tank. 1

3. Remove bukket cylinder assembly. For details, see REMOVAL OF BUCKET CYLINDER ASSEMBLY. 4. Remove bolt (3), then remove cover (4).

5. Remove bolt (5), and loosen bolt (6), then rotate cover (7) carefully to right. ★ Rotate the cover on the right side of the chassis to the left. ★ Rotate the cover using bolt (6) as the fulcrum. ★ The operating space is confined, so be extremely careful when carrying out the operation.

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WF550-3 / WF550T-3



6. Disconnect hose (13) for bucket spool between PPC valve (P1) and main control valve (PB1).

7. Disconnect hose (14) for boom spool between PPC valve (P3) and main control valve (PB2). 8. Disconnect hose (15) for bucket spool between PPC valve (P4) and main control valve (PA1). 9. Disconnect hose (16) for boom spool between PPC valve (P2) and main control valve (PA2). ★ Remove the hose clamp. ★ After disconnecting the hose, move it to the rear of the machine. ★ After disconnecting the hoses, fit tags to distinguish them.

10. Disconnect hose (17) between main control valve and hydraulic tank.

Front of machine

11. Remove tube (18) between main control valve and bucket cylinder together with hose. 12. Remove tube (19) between main control valve and boom cylinder. 13. Disconnect tube (20) from manifold. 14. Remove bracket (21) of tube.

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15. Disconnect hose (22) between steering valve and main control valve from main control valve. 16. Disconnect tube (23) between hydraulic tank and main control valve from main control valve.

17. Remove tube (24) between main control valve and bucket cylinder together with hose. 18. Disconnect tube (25) between main control valve and boom cylinder from main control valve. ★ Loosen the tube clamp.

19. Remove mounting bolts and rotate main control valve (26) 90°.

20. Using eyebolts, lift off main control valve. ★ Be careful of the slack adjuster bleed screw when removing.

Main valve: 91 kg

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WF550-3 / WF550T-3



Installation (WF550-3) Carry out installation in the reverse order to removal. 1 t Plug: 11.8 ± 1.0 Nm {1.2 ± 0.1 kgm} Refilling with oil (hydraulic tank) Add oil through oil filler to the specified level. Run the engine to circulate the oil through the system. Then check the oil level again.

Removal (WF550T-3)

• Stop the machine on level ground, install the safety bar on the frame, and put blocks under the steel wheels to prevent the machine from moving. • Loosen the oil filler cap slowly to release the pressure inside the hydraulic tank. Then operate the steering wheel and control levers several times to release the remaining pressure in the hydraulic piping. 1. Open cover (1). 2. Loosen plug (2) on top of the hydraulic tank filter and bleed air from tank. 1

3. Remove bolt (3), then remove cover (4).

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4. Disconnect hose (5) between PPC valve (P2) and main control valve (P2B). (Boom LOWER) 5. Disconnect hose (6) between PPC valve (P3) and main control valve (P2A). (Boom RAISE)

Control valve

6. Remove tubes (7) and (8) between main control valve and boom cylinder.

Front Frame

To Lift Cylinder

Control valve

7. Remove tube (9) between main control valve and pump. ★ Disconnect hose (10).

Control valve Steering demand valve

8. Remove tube (11) between main control valve and hydraulic tank.

Control valve

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WF550-3 / WF550T-3



9. Remove mounting bolts, and lift off main control valve (12). ★ Move the main control valve to the rear and lift it up above the front frame.

Main control valve: 75 kg

Installation (WF550) Carry out installation in the reverse order to removal. 1 t Plug: 11.8 ± 1.0 Nm {1.2 ± 0.1 kgm} Refilling with oil (hydraulic tank) Add oil through oil filler to the specified level. Run the engine to circulate the oil through the system. Then check the oil level again.

WF550-3 / WF550T-3

30-61



Disassembly For the WF550-3, see the shop manual for the WA500-3, Serial No.: 50001 and up.

WF550T-3

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WF550-3 / WF550T-3



1. Spool assembly a. Remove case (1), then remove retainer (2) and spring (3). b. Remove bolt (4), washer (5), and retainer (6). c.

Remove spring (7), retainer (8), and collar (9).

d. Remove retainer (10), then remove spool (11). e. Remove case (12), then remove retainer (13) and spring (14). f.

Remove retainer (15), spring (16), and retainer (17).

2. Main relief valve a. Remove main relief valve assembly (18). ★ Disassemble the main relief valve assembly.

I.

Loosen locknuts (19) and (19-1), and screw (20).

★ Before loosening nut (19), measure the dimension from the end face of holder (22) to the tip of the nut.

II. Loosen nut (21), then remove holder (22), retainer (23), spring (24), spacer (25), and pivot (26). III. Remove seat (27), spring (28), and valve (29). IV. Remove plug (30). 3. Suction-safety valve a. Remove safety valve assembly (32). ★ The safety valve cannot be adjusted when it is installed on the machine, so do not disassemble it.

4. Suction valve a. Remove suction valve assembly (33). ★ Disassemble suction valve assembly.

I.

Remove valve (34) together with seal (35).

II. Remove seal (35) from valve (34). III. Remove spring (36) from sleeve (37). ★ If there is any abnormality in the sleeve or valve, replace as an assembly.

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5. Check valve assembly a. Remove plug (38), then remove spring (39) and check valve (40).

6. Cover valve assembly a. Remove cover valve assembly (42) from valve body (41). ★ Disassemble the cover valve assembly.

I.

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Remove plate (43), then remove seat (44), spring (45), and valve (46).

WF550-3 / WF550T-3




WF550-3 / WF550T-3

30-65



Assembly For the WF550-3, see the shop manual for the WA500-3, Serial No.: 50001 and up.

WF550T-3

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WF550-3 / WF550T-3



1. Cover valve assembly ★ Assemble the cover valve assembly.

a. Assemble valve (46) and spring (45) to cover valve assembly (42), then fit O-ring to seat (44) and install plate (43). t Mounting bolt: 59 – 73 Nm {6 – 7.5 kgm}

b. Fit O-ring to valve body (41) and install cover valve assembly (42). ★ Tighten the mounting bolts in the order shown in the diagram on the right.

t Mounting bolt: 108 ± 10 Nm {11 ± 1 kgm}

2. Check valve assembly a. Assemble check valve (40) and spring (39), then fit O-ring to plug (38) and install.

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30-67



3. Suction valve assembly ★ Assemble suction valve assembly (33).

a. Assemble spring (36) to sleeve (37). b. Fit seal (35) to valve (34), and install to sleeve (37). c.

Fit O-ring and install suction valve assembly (33). t Suction valve assembly: 216 – 235 Nm {22 – 24 kgm}

4. Suction safety valve a. Fit O-ring and install safety valve assembly (32). t Safety valve: 216 – 235 Nm {22 – 24 kgm} 5. Main relief valve assembly ★ Assemble main relief valve assembly.

I.

Assemble valve (29) and spring (28) in sleeve (31).

II. Install plug (30) to sleeve (31). r Plug: Thread tightener (LT-2) III. Fit O-ring and backup ring to seat (27), and assemble in sleeve (31). IV. Assemble retainer (23), spring (24), spacer (25), and pivot (26) in holder (22). V. Fit O-ring and install holder assembly to sleeve (31), then secure with nut (21). t Holder assembly: 29.4 – 49 Nm {3 – 5 kgm} t Nut: 93.2 – 122.6 Nm {9.5 – 12.5 kgm} VI. Screw in screw (20), and set nuts (19-1) and (19) to dimensions of protrusion from end face of holder (22) measured during disassembly. t Nut (19-1): 28 – 34 Nm {2.8 – 3.5 kgm} t Nut (19): 28 – 34 Nm {2.8 – 3.5 kgm} a. Fit O-ring and install main relief valve assembly (18). t Main relief valve: 127 – 177 Nm {13 – 18 kgm}

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WF550-3 / WF550T-3



6. Spool assembly a. Assemble spool (11) in valve body. b. Assemble retainer (17), spring (16), and retainer (15). c.

Assemble spring (14) and retainer (13), then fit O-ring to case (12) and install.

d. Install retainer (10). e. Assemble retainer (8), collar (9), and spring (7). f.

Assemble washer (5) and retainer (6) to bolt (4), then install to spool (11). t Bolt: 11.8 – 14.7 Nm {1.2 – 1.5 kgm}

g. Assemble spring (3) and retainer (2), then fit O-ring to case (1) and install.

WF550-3 / WF550T-3

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Lift cylinder assembly


Lift cylinder assembly Removal (WF550T-3)

Fit the safety bar, lower the work equipment completely to the ground, then apply the parking brake and put blocks securely under the steel wheels.

1. Sling cylinder and remove head pin (1).

1

Front Frame

2. Start engine, retract piston rod and tie it with wire to prevent piston rod from coming out.

Loosen the oil filler cap slowly to release the pressure inside the hydraulic tank, then operate the control levers several times to release the remaining pressure in the hydraulic piping.

3. Disconnect hoses (2) and (3). ★ Fit blind plugs in the tubes and hoses after disconnecting.

4. Remove bottom pin (4) and lift off lift cylinder assembly (5). 2

Lift cylinder assembly: 160 kg

30-70

WF550-3 / WF550T-3


Lift cylinder assembly

Installation (WF550T-3) Carry out installation in the reverse order to removal. 1

2

When aligning the position of the pin hole, use a bar. Never insert your fingers in the pin hole.

Refilling with oil (hydraulic tank) Run the engine to circulate the oil through the system. Then add oil to the specified level.

WF550-3 / WF550T-3

30-71

Boom, bucket and lift cylinders assembly


Boom, bucket and lift cylinders assembly Disassembly 1. Set cylinder assembly (1) tool U1. 2. Remove mounting bolts (2) of cylinder head.

3. Pull cylinder head and piston rod assembly (3) out from cylinder (4), then lift off. ★ Oil will come out when the piston rod assembly is removed from the cylinder, so catch it in a container.

4. Remove piston bolts (5), then remove spacer (6), piston assembly (7) and cylinder head assembly (8).

5. Remove O-ring (10) and backup ring (11) from piston rod (9).

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WF550-3 / WF550T-3



6. Disassembly of piston assembly Remove wear ring (12) and piston ring (13) from piston (14).

7. Disassembly of cylinder assembly a. Remove O-ring (15) and backup ring (16). b. Remove snap ring, then remove dust seal (17).

c.

Remove rod packing (18).

d. Remove bushing (19).

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Assembly ★ Clean all parts, and check for dirt or damage. Coat the sliding surfaces of all parts with engine oil before installing. Be careful not to damage the U-packings, dust seals or O-ring when assembling.

1. Assembly of cylinder head assembly a. Using push tool U5, press fit bushing (19) on cylinder head (20). ★ Be careful not to deform the bushing when press fitting.

b. Assemble rod packing (18). ★ Be careful to install the rod packing facing in the correct direction.

c.

Assemble buffer ring (21).

d. Assemble backup ring (16) and O-ring (15) in order. ★ Do not try to force the backup ring into position. Warm it in warm water (50 – 60°C) before fitting it.

e. Using push tool U4, install dust seal (17) to cylinder head, then secure with snap ring.

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WF550-3 / WF550T-3



2. Assembly of piston assembly a. Using tool U6-1, expand piston ring (13). ★ Set the piston ring on the expander and turn the handle 8 – 11 times to expand the ring.

b. Remove piston ring from tool U6-1, and assemble on piston (14). c.

Fit tools U6-2, on piston ring, then using clamp U6-3, compress piston ring.

d. Assemble wear ring (12) on piston.

3. Assemble O-ring (10) and backup ring (11) on piston rod (9).

4. Assemble cylinder head assembly (8) and piston assembly (7) on piston rod. ★ Coat backup ring (11) with grease so that it does not stick out, and assemble carefully.

5. Assemble spacer (6), then tighten piston bolts (5). t Piston bolt: 176.5 ± 19.6Nm {18.0 ± 2.0 kgm}(WF550-3) 110.25 ± 12.25Nm{11.25 ± 1.25 kgm}(WF550T-3) r Piston bolt: Adhesives (LT-2)

WF550-3 / WF550T-3

30-75



6. Set cylinder (4) in tool U1, then raise piston rod and head assembly (3), and assemble in cylinder (4).

•

Tighten cylinder head mounting bolts (2). t Cylinder head mounting bolt: 662 ± 74Nm {67.5 ± 7.5kgm}(WF550-3) 162 ± 14.5Nm {16.5 ± 1.5 kgm}(WF550T-3)

•

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Remove cylinder assembly (1) from tool U1.

WF550-3 / WF550T-3


Work equipment assembly

Work equipment assembly Removal (WF550T-3) For the WF550-3, see the shop manual for the WA500-3, Serial No.: 50001 and up.

Fit the safety bar, lower the work equipment completely to the ground, then apply the parking brake and put blocks securely under the steel wheels. 1. Set blocks and sides of the blade.

ô under the arm and the left and right

2. Sling lift cylinder assembly (3) and remove head pin (4). 1 3. Start engine retract piston rod and tie it with wire to prevent piston rod from coming out.

• Loosen the oil filler cap slowly to release the pressure inside the hydraulic tank, then operate the control levers several times to release the remaining pressure in the hydraulic piping. • Open cover (1) at the top of the hydraulic tank, then remove plug (2) at the top of the hydraulic filter and release the pressure remaining inside the hydraulic filter.

4. Remove pin (5).

2

5. Start engine, then move machine slowly in reverse to disconnect work equipment assembly (6).

WF550-3 / WF550T-3

30-77

Work equipment assembly


Installation (WF550T-3) For the WF550-3, see the shop manual for the WA500-3, Serial No.: 50001 and up. Carry out installation in the recerses order to removal. 1 2

When aligning the position of the pin hole, use a bar. Never insert your fingers in the pin hole.

2 ★ Adjust with shims so that clearance a + b = Less than 1.5 mm. ★ Be carefull not to get cord ring (7) caught. ★ Grease each pin.

r Grease: (G2-LI)

30-78

WF550-3 / WF550T-3


Engine hood assembly

Engine hood assembly Removal

Stop the machine on level ground, set the parking brake to the PARKING position, and put blocks under the steel wheels to prevent the machine from moving.

★ Open the left and right inspection covers.

1. Remove exhaust tube (1) and precleaner. 2. Remove radiator grill (2). ★ Remove the baffle plate on both sides of the radiator.

3. Disconnect head lamp connector (3). 4. Disconnect water level sensor connector (4).

5. Remove 6 mounting bolts (5) and 4 mounting bolts (6).

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Engine hood assembly


6. Remove radiator support (7). 7. Lift off engine hood (8). ★ There are clamps for the air conditioner hoses at 2 places inside the engine hood on the right, so disconnect them. ★ Use a lever block to maintain the balance when lifting off.

Engine hood assembly: 470 kg


30-80

WF550-3 / WF550T-3


Floor frame assembly

Floor frame assembly Removal

Stop the machine on level ground, install the safety bar on the frame, and put blocks under the wheels to prevent the machine from moving.

1. Remove cab assembly. For details, see REMOVAL OF CAB ASSEMBLY. 2. Remove left and right guard, floor (1) and (2).

3. Remove floor plate (4) and cover (3) of bulkhead. 4. Disconnect wiring connectors (5) (TM1,2, LR1 - 6). 5. Disconnect ground connection (6).

6. Disconnect hoses (7) between brake valve and slack adjuster. 7. Disconnect hose (9) between Orbit-roll (8) and hydraulic tank. 8. Disconnect hose (10) between Orbit-roll (8) and accumulator. 9. Disconnect hoses (11) between Orbit-roll (8) and stop valve.

WF550-3 / WF550T-3

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10. Disconnect return hose (12) between Orbit-roll valve and hydraulic tank. 11. Disconnect return hose (13) coming from PPC valve. 12. Disconnect return hose (14) coming from brake valve. ★ After disconnecting the hose, fit a blind plug.

13. Remove mounting bolts (15), then remove brake hose bracket (16). 14. Disconnect PPC hoses (17) and (17-1). ★ There is no hose (17-1) on the WF550T-3. ★ The hoses are fitted with self-seal couplings.

15. Disconnect hose (18) from PPC pump.

16. Disconnect accumulator charge valve connecting hoses (19) and (20). 17. Disconnect PPC accumulator connecting hose (21). 18. Disconnect 2 window washer hoses (22). 19. Disconnect 2 hoses (23) from brake valve.

20. Disconnect air conditioner compressor hose (24).

1

★ There are hose clamps at 2 places inside the engine hood, so remove them.

21. Remove clamp (25) and joint (26), then remove accelerator cable (27).

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WF550-3 / WF550T-3



22. Disconnect heater hoses (28) and (29). ★ Hose (29) is installed under the connector at the suction end of the water pump. ★ Drain the coolant.

23. Remove floor frame mount mounting nuts (30) (4 places).

2

24. Lift off floor frame assembly (31). ★ When lifting off, check that all the clamps and wiring harnesses have been disconnected.

Floor frame assembly: 280kg

WF550-3 / WF550T-3

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Installation Carry out installation in the reverse order to removal. 1 ★ Install the hoses without twisting or interference. ★ When installing the hoses, be careful not to let dirt, dust, or moisture get inside the hoses. ★ Using a gas charger (X3), charge with new freon gas (R134a).

2 t Mount nut: 277.3 ± 32.3 Nm {28.3 ± 3.3 kgm} Refilling with water Tighten radiator drain valve and add water through water filler to the specified level. Run the engine to circulate the water through the system. Then check the water level again.

30-84

WF550-3 / WF550T-3


Fuel tank assembly

Fuel tank assembly Removal


1. Loosen drain valve and drain fuel. ★ Check the fuel level before draining. Fuel (when full): 630 l

2. Disconnect hose (1) between injection pump and fuel tank. 3. Disconnect hose (2) between feed pump and fuel tank. 4. Disconnect spill hose (3). 5. Disconnect breather hose (4).

6. Disconnect connector (5) for fuel level sensor. 7. Sling fuel tank assembly (6), then remove mounting bolts and lower slowly.


WF550-3 / WF550T-3

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Air conditioner condenser assembly


Air conditioner condenser assembly Removal


1. Disconnect connector (1) (E12). 2. Install freon gas collector and regenerator to plugs (2), and collect refrigerant.

3. Disconnect hose (3) between condenser and air conditioner compressor. 1 ★ Always fit a wrench to the compressor side.

4. Disconnect hose (4) between receiver tank and condenser. 2 5. Remove mounting bolts, then remove condenser assembly (5).

Installation Carry out installation in the reverse order to removal. 1 2 ★ Install the hoses without twisting or interference. ★ When installing the hoses, be careful not to let dirt, dust, or moisture get inside the hoses. ★ Using a gas charger (X3), charge with new freon gas (R134a).

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WF550-3 / WF550T-3


Reciver tank

Reciver tank Removal


1. Disconnect connector (1) (E12). 2. Install freon gas collector and regenerator to plug (2), and collect refrigerant.

3. Disconnect hose (3) between receiver tank and air conditioner unit. 1 4. Disconnect hose (4) between receiver tank and condenser. 2 5. Remove U-bolts (5), then remove receiver tank assembly (6).

Installation 1

2

★ Install the hoses without twisting or interference. ★ When installing the hoses, be careful not to let dirt, dust, or moisture get inside the hoses. ★ Using a gas charger (X3), charge with new freon gas (R134a).

WF550-3 / WF550T-3

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Reciver tank



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WF550-3 / WF550T-3

40 MAINTENANCE STANDARD Engine mount . . . . . . . . . . . . . . . . . . . . . . . . . 40-2

ROPS cab . . . . . . . . . . . . . . . . . . . . . . . . . . . .40-53

Transmission mount . . . . . . . . . . . . . . . . . . . 40-3 Damper . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40-4 Torque converter charging pump . . . . . . . . . 40-5 Torque converter, PTO . . . . . . . . . . . . . . . . . 40-6 Transmission . . . . . . . . . . . . . . . . . . . . . . . . . 40-8 Transfer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40-12 Main relief, torque converter relief valve . . 40-14 Lubrication relief valve . . . . . . . . . . . . . . . . 40-15 Drive shaft . . . . . . . . . . . . . . . . . . . . . . . . . . . 40-16 Center support . . . . . . . . . . . . . . . . . . . . . . . 40-17 Differential . . . . . . . . . . . . . . . . . . . . . . . . . . 40-18 Final drive . . . . . . . . . . . . . . . . . . . . . . . . . . . 40-20 Axle mount . . . . . . . . . . . . . . . . . . . . . . . . . . 40-21 Center hinge pin . . . . . . . . . . . . . . . . . . . . . . 40-22 Steering column . . . . . . . . . . . . . . . . . . . . . . 40-24 Steering pump . . . . . . . . . . . . . . . . . . . . . . . 40-25 Steering valve . . . . . . . . . . . . . . . . . . . . . . . . 40-26 Steering cylinder mount . . . . . . . . . . . . . . . 40-27 Brake valve . . . . . . . . . . . . . . . . . . . . . . . . . . 40-28 Slack adjuster . . . . . . . . . . . . . . . . . . . . . . . . 40-30 Brake . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40-31 Parking brake . . . . . . . . . . . . . . . . . . . . . . . . 40-32 Hydraulik pump . . . . . . . . . . . . . . . . . . . . . . 40-33 WF550T-3 . . . . . . . . . . . . . . . . . . . . . . . . . . . 40-33 WF550-3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40-34 Switch, PPC pump . . . . . . . . . . . . . . . . . . . . 40-35 PPC valve . . . . . . . . . . . . . . . . . . . . . . . . . . . 40-36 WF550T-3 . . . . . . . . . . . . . . . . . . . . . . . . . . . 40-36 WF550-3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40-37 Main control valve . . . . . . . . . . . . . . . . . . . . 40-38 WF550T-3 . . . . . . . . . . . . . . . . . . . . . . . . . . . 40-38 WF550-3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40-40 Cut-off valve . . . . . . . . . . . . . . . . . . . . . . . . . 40-42 WF550-3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40-42 Hydraulic cylinders . . . . . . . . . . . . . . . . . . . 40-44 WF550T-3 . . . . . . . . . . . . . . . . . . . . . . . . . . . 40-44 WF550-3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40-46 Work equipment linkage . . . . . . . . . . . . . . . 40-48 WF550T-3 . . . . . . . . . . . . . . . . . . . . . . . . . . . 40-48 WF550-3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40-50 Bucket positioner and boom kick-out . . . . 40-52 WF550-3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40-52 WF550-3 / WF550T-3

40-1

Engine mount

MAINTENANCE STANDARD

Engine mount

Unit: mm No.

Check item

Criteria

Remedy

1

Clearance between engine damper and trunnion support

3.0 – 7.0

Adjust

40-2

WF550-3 / WF550T-3


Transmission mount

Transmission mount

Unit: mm No.

Check item

Criteria

Remedy

1

Thickness of shim for mounting

Shim thickness: 0.5 mm decide the shim thickness so that the misalignment between the damper output shaft and input shaft is less than 2.0 mm

Adjust

2

Clearance between stopper and bracket

There must be a clearance of at least 2 mm between the stopper and bracket around the whole circumference

WF550-3 / WF550T-3

40-3

Damper


Damper

Unit: mm No.

Check item

Criteria Tolerance Shaft

Hole

Standard clearance

40

–0.009 –0.034

0 –0.012

–0.003 – 0.034

0.05

Standard size 1

Remedy

Clearance between bearing and shaft

Clearance limit

2

Clearance between bearing and housing

80

0 –0.013

0 –0.030

–0.030 – 0.013

0.035

3

Clearance between bearing and shaft

75

+0.012 –0.007

0 –0.015

–0.027 – 0.007

0.025

4

Clearance between bearing and cover

130

0 –0.018

+0.018 +0.007

0.007 – 0.036

0.05

5

Clearance between retainer and cover

135

–0.014 –0.054

+0.04 0

0.014 – 0.094

0.13

6

Wear of surface in coupling and oil seal

7

Wear of surface in shaft and seal

8

Backlash of spline (shaft, coupling and body)

40-4

Standard size

Tolerance

Repair limit

95

0 –0.087

–0.12

105

0 –0.087

–0.12

Replace

0.071 – 0.177

WF550-3 / WF550T-3



Torque converter charging pump SAR(3)-80

Unit: mm No.

1

Check item Clearance between gear case and side plate, gear

2

Clearance between inside diameter of plain bearing and outside diameter of gear shaft

3

Insertion depth of pin

4

Rotating torque of spline shaft

–

Discharge Oil: EO10-CD Temperature: 45 – 55°C

Criteria Standard clearance

Clearance limit

0.10 – 0.15

0.19

0.06 – 0.149

0.20

Replace

0

14 -0.5 6.9 – 11.8 Nm {0.7 – 1.2 kgm} Revolution (rpm) 2,500

WF550-3 / WF550T-3

Remedy

Pressure MPa{kg/cm2} 3.5 {35.9}

–

Standard Discharge (l/min.)

Repair limit discharge (l/min.)

184

170

–

40-5

Torque converter, PTO



Unit: mm No.

Check item

1

Outside diameter of coupling oil seal contact surface

Criteria

Remedy

Standard size

Tolerance

Repair limit

95

0 –0.087

94.8

2

Inside diameter of retainer seal ring contact surface

120

+0.035 0

120.5

3

Inside diameter of sleeve seal ring contact surface

65

+0.025 0

65.1

Width and thickness of seal ring

Width

3.95

0 –0.1

3.55

4

Thickness

4.6

±0.1

4.14

5

40-6

Backlash of PTO gear

Repair hard chrome plating or replace

Replace

0.18 – 0.49

WF550-3 / WF550T-3




WF550-3 / WF550T-3

40-7

Transmission


Transmission (1/2)

40-8

WF550-3 / WF550T-3


Transmission

Unit: mm No.

Check item

Criteria

Remedy

Standard size 1

No. 1 clutch spring (x 10)

Repair limit

Free length

Installed length

Installed load

Free length

Installed load

66

56.5

132.4 N {13.5 kg}

62.0

112.8 N {11.5 kg}

2


59

52.5

63.7 N {6.5 kg}

55.5

53.9 N {5.5 kg}

3


39.8

33.5

87.3 N {8.9 kg}

37.4

74.5 N {7.6 kg}

4

No. 4 clutch spring (10 each)

39.8

35.9

54.1 N {5.5 kg}

37.4

46.0 N {4.7 kg}

5


39.8

35.0

66.6 N {6.8 kg}

37.4

56.6 N {5.8 kg}

6

No. 6 clutch spring (10 each)

39.8

34.2

77.5 N {7.9 kg}

37.4

65.7 N {6.7 kg}

Overall thickness of 4 discs and 4 plates for No. 1 clutch

Standard size

Tolerance

Repair limit

7

40

±0.28

36.3

8


40

±0.28

36.3

9


25

±0.22

22.6

10


25

±0.22

22.6

11

Overall thickness of 3 discs and 2 plate for No. 5 clutch

21.4

±0.22

19.0

12

Overall thickness of 3 discs and 2 plate for No. 6 clutch

25

±0.22

22.6

13

Thickness of 1 disc

5

±0.1

4.2

14

Thickness of 1 plate (No.1–4, No.6 clutch)

5

±0.1

4.5

15

Thickness of 1 plate (No.5 clutch)

3.2

±0.1

2.9

16

Clearance between transmission input shaft bearing and housing

Replace

Tolerance Shaft

Hole

Standard clearance

90

0 –0.015

+0.016 –0.006

+0.031 – –0.006

+0.037

Standard size

Clearance limit

17

Clearance between transmission output shaft bearing and carrier

72

0 –0.013

+0.013 –0.006

+0.026 – –0.006

+0.031

18

Clearance between transmission output shaft bearing and housing

100

0 –0.015

+0.016 –0.006

+0.031 – –0.006

+0.037

WF550-3 / WF550T-3

40-9

Transmission


(2/2)

40-10

WF550-3 / WF550T-3


Transmission

Unit: mm No.

1

Check item

Wear of trans-mission inputshaft seal ring

Width

Thickness

Wear of trans-mission output shaft seal ring

Width

Inside diameter of sleeve seal ring contact surface

Thickness

Criteria

Remedy

Standard size

Tolerance

Repair limit

3

–0.01 –0.03

2.7

2.7

±0.1

2.55

3

–0.01 –0.03

2.7

2.7

±0.1

2.95

2

3

Backlash between No. 1 sun gear and planet gear

0.13 – 0.32

4

Backlash between No. 1 planet gear and ring gear inside teeth

0.15 – 0.38

5


0.13 – 0.32

6


0.15 – 0.38

7


0.12 – 0.30

8


0.15 – 0.38

9


0.13 – 0.32

10


0.15 – 0.38

11


0.14 – 0.35

12


0.15 – 0.38

WF550-3 / WF550T-3

Replace

40-11

Transfer


Transfer

40-12

WF550-3 / WF550T-3


Transfer

Unit: mm No.

Check item


Hole

Standard clearance

85

+0.045 +0.023

0 –0.020

–0.023 – –0.065

Standard size 1

Remedy

Clearance between drive gear and bearing

2

Clearance between drive gear bearing and cage

150

0 –0.018

–0.012 –0.052

0.006 – –0.052

3

Clearance between drive gear bearing and cage

150

0 –0.018

0 –0.040

0.018 – –0.040

4

Clearance between idler gear and bearing

95

+0.059 –0.037

0 –0.020

–0.037 – 0.079

5

Clearance between drive gear bearing and case (cover)

170

0 –0.025

0 –0.040

0.025 – –0.040

6

Clearance between output shaft and bearing

80

+0.039 –0.020

0 –0.015

–0.020 – –0.054

7

Clearance between output shaft bearing and cage

140

0 –0.018

–0.012 –0.052

0.006 – –0.052

8

Clearance between spacer and bearing

95

+0.045 +0.023

0 –0.020

–0.023 – –0.065

9

Clearance between output shaft bearing and housing

170

0 –0.025

–0.012 –0.052

0.013 – –0.052

10

Coupling oil seal contact surface

Replace

Standard size

Tolerance

Standard clearance

95

0 –0.018

94.8

Standard clearance Clearance between cage and case

Clearance limit

Clearance limit

2 (shim)

Preload: 0.1 – 1.0 Nm {0.01 – 0.1 kgm} (Drive gear as individual part)

12

Clearance between cover and case

2 (shim)

Preload: 0.3 – 0.55 Nm{0.03 – 0.055 kgm} Then add 0.1 mm of shim (Idler gear as individual part)

13

Clearance between cage and cover

0.25 (shim)

14

Backlash between drive gear and idler gear

0.17 – 0.44

15

Backlash between idler gear and driven gear

0.17 – 0.44

11

Adjust

Preload: 0.5 – 1.0 Nm {0.05 – 0.1 kgm} (Output shaft as individual part)

Replace

WF550-3 / WF550T-3

40-13




Unit: mm No.

Check item

Criteria Tolerance Hole

Standard clearance

Clearance limit

Shaft 25

–0.035 –0.045

+0.013 0

0.035 – 0.058

0.08

22

–0.035 –0.045

+0.013 0

0.035 – 0.058

0.08

Standard size 1

2

Clearance between main relief valve and valve body

Clearance between torque converter relief valve and valve body

Remedy

Standard size 3

Main relief valve spring (outer)

Repair limit

Free length

Installed length

Installed load

Free length

Installed load

128

75.3

509 N {51.9 kg}

124.2

483 N {49.3 kg}

4

Main relief valve spring (inner)

108

75.3

402 N {41.0 kg}

104.8

382 N {39.0 kg}

5

Main relief valve spring

50

42

153 N {15.6 kg}

48.5

145 N {14.8 kg}

40-14

Replace

WF550-3 / WF550T-3


Lubrication relief valve


Unit: mm No.

Check item

Criteria

Remedy

Standard size 1

Lubrication relief valve spring

WF550-3 / WF550T-3

Repair limit

Free length

Installed length

Installed load

Free length

Installed load

26

23.7

11.8 N {1.2 kg}

25.2

10.8 N {1.1 kg}

Replace

40-15

Drive shaft


Drive shaft Machine body shows WF550-3.

40-16

WF550-3 / WF550T-3


Center support

Center support

Unit: mm No.

Check item


Standard clearance

Clearance limit

Shaft 140

0 –0.018

–0.036 –0.061

–0.018 – –0.016

–0.015

Standard size 1

Remedy

Clearance between case and bearing

2

Clearance between case and bearing

130

0 –0.018

–0.036 –0.061

–0.018 – –0.016

–0.015

3

Clearance between coupling shaft and bearing

80

+0.051 +0.032

0 –0.015

0.032 – 0.066

0.029

4

Clearance between coupling shaft and bearing

75

+0.051 +0.032

0 –0.015

0.032 – 0.066

0.029

5

Wear of oil seal surface

6

Wear of seal surface

7

End play of coupling shaft

WF550-3 / WF550T-3

Standard size

Tolerance

Repair limit

95

0 –0.087

–0.18

105

0 –0.087

–0.18

Preload max. 3.9 Nm {0.4 kgm}

Replace

Repair chrome plating or replace Replace

40-17

Differential


Differential

40-18

WF550-3 / WF550T-3


Differential

Unit: mm No.

Check item

1

Clearance of side bearing outer race in differential gear assembly

Criteria Tolerance

Remedy

Shaft

Hole

Standard clearance

180

0 –0.025

+0.026 +0.014

0.014 – 0.051

–

120

+0.045 +0.023

0 –0.025

–0.023 – –0.065

–

Standard size

Clearance limit

2

Clearance of side bearing inner race in differential gear assembly

3

Clearance of outer race of pinion shaft bearing

171.45

+0.025 0

+0.026 –0.014

0.026 – –0.039

–

4

Clearance of inner race of pinion shaft bearing

76.2

+0.064 +0.038

+0.013 0

–0.025 – 0.064

–

5

Clearance of inner race of pinion shaft bearing

76.2

+0.030 +0.011

+0.013 0

0.002 – –0.030

–

6

Clearance of inner race of pilot bearing

55

+0.039 +0.020

–0.010 –0.025

–0.030 – –0.064

–

7

Clearance between differential carrier and cage

210

–0.020 –0.060

+0.046 +0.010

0.030 – 0.106

–

8

Backlash of bevel gear

0.30 – 0.41

9

Backlash of differential gear

0.30 – 0.41

10

End play of pinion gear

11

Free rotating torque of bevel gear

12

Rear face runout of bevel gear

13

Standard thickness of shims for stop shaft

Replace

Max. 0.64 Max. 8.34 Nm {0.85 kg} 0.1 Clearance "a" + (0.1 ± 0.05) Standard size

Tolerance

Standard clearance

±0.025

3.6

±0.035

3.915

3.705 14

Thickness of plate 3.785 3.855

15

Thickness of disc

16

Clearance of disc, plate (End play)

17

Thickness of washer

3.96

±0.2

3.8

18

Wear of oil seal surface

100

0 –0.087

–

WF550-3 / WF550T-3

3.965

0.2 – 0.8

40-19

Final drive


Final drive

Unit: mm No.

Check item


Standard clearance

Clearance limit

Shaft 55

+0.015 +0.002

0 –0.015

–0.002 – –0.030

–

215.9

+0.060 +0.013

+0.025 0

–0.012 – –0.060

–

Standard size 1

Clearance between planetary shaft and bearing

2

Clearance between ring gear hub and bearing

3

Thickness of spacer

Standard size

Tolerance

Repair limit

22

+0.1 –0.1

21.5

4

Backlash between planetary gear and sun gear

0.18 – 0.45

5

Backlash between planetary gear and ring gear

0.21 – 0.62

6

Thickness of standard shim for wheel hub

40-20

Remedy

Replace

2.0

WF550-3 / WF550T-3


Axle mount

Axle mount Machine body shows WF550-3.

Unit: mm No.

Check item

1

Crearance of shaft and hole Front support side (After press-fitting bushing)


Standard clearance

Clearance limit

Shaft –0.056 –0.137

+0.489 0

0.056 – 0.626

1.6

Standard size

310

Remedy

Replace

2

Clearance of shaft and hole Front support side (Before installing bushing)

320.2

+2.300 +0.800

+0.089 0

–

–

3

Clearance of shaft and hole Rear support side (After press-fitting bushing)

260

–0.056 –0.137

+0.481 –0.008

0.048 – 0.618

1.6

4

Clearance of shaft and hole Rear support side (Before installing bushing)

270.2

+2.300 +0.800

+0.081 0

–

–

5

Thickness of wear plate

Standard size

Tolerance

Repair limit

20

–0.10 –0.25

–

6

Thickness of wear plate

5

+0.1 –0.3

–

7

Thickness of rear bushing

5

±0.1

–

8

Thickness of front bushing

5

±0.1

–

WF550-3 / WF550T-3

The bushings must be in contact with the support at both the front and rear.

Replace

40-21

Center hinge pin


Center hinge pin Machine body shows WF550-3.

(When adjusting shim) (Final value)



40-22

WF550-3 / WF550T-3


Center hinge pin

Unit: mm No.

Check item


Hole

Standard clearance

100

–0.036 –0.058

+0.054 0

0.036 – 0.112

–

Standard size 1

Remedy

Clearance between lower hinge pin and rear frame

Clearance limit

2

Clearance between lower hinge pin and spacer (small)

100

–0.036 –0.058

+0.054 0

0.036 – 0.112

–

3

Clearance between lower hinge pin and bearing

100

–0.036 –0.058

0 –0.020

0.016 – 0.058

–

4

Clearance between lower hinge pin and spacer (large)

100

–0.036 –0.058

+0.054 0

0.036 – 0.122

–

5

Clearance between rear frame and spacer (large)

130

–0.043 –0.106

+0.063 0

0.043 – 0.169

–

6

Clearance between front frame and upper hinge bearing

155

0 –0.025

–0.048 –0.088

–0.023 – –0.088

–

7

Clearance between upper hinge pin and rear frame

100

–0.036 –0.058

+0.054 0

0.036 – 0.112

–

8

Clearance between upper hinge pin and bearing

100

–0.036 –0.058

0 –0.020

0.016 – 0.058

–

9

Clearance between front frame and lower hinge bearing

160

0 –0.025

–0.050 –0.090

–0.025 – –0.090

–

10

Clearance between rear frame and bushing

125

–0.043 –0.083

+0.063 0

0.043 – 0.146

–

11

Clearance at press-fitted part of seal of upper hinge pin

115

+0.280 +0.180

+0.054 0

–0.126 – –0.28

–

12

Clearance at press-fitted part of seal of lower hinge pin

135

+0.310 +0.210

+0.063 0

–0.147 – –0.31

–

13

Height of lower hinge spacer (small)

Standard size

Tolerance

Standard clearance

35

±0.1

–

101.5

±0.1

–

14

Height of lower hinge spacer (large)

15

Shim thickness for lower hinge and retainer

2.3

16

Shim thickness for lower hinge and retainer

1.6

17

Shim thickness for upper hinge and retainer

1.6

WF550-3 / WF550T-3

Replace

Adjust

40-23

Steering column


Steering column

Unit: mm No.

Check item


Hole

Standard clearance

0 –0.080

+0.150 +0.050

0.05 – 0.23

Standard size 1

Clearance between steering shaft and column bushing 19

40-24

Remedy

Clearance limit Replace 0.4

WF550-3 / WF550T-3


Steering pump

Steering pump SAR(3)-080

Unit: mm No.

1


2


3


4


–

Discharge EO10-CD 45 – 55°C


Clearance limit

0.10 – 0.15

0.19

0.06 – 0.149

0.20

Replace

0


WF550-3 / WF550T-3

Remedy

Discharge pressure MPa{kg/cm2} 20.6 {210}

Standard discharge (l/min.)


184

170

–

40-25

Steering valve


Steering valve

Unit: mm No.

Check item

Criteria

Remedy

Standard size 1

Steering spool return spring

Repair limit

Free length

Installed length

Installed load

Free length

Load limit

37.2

32.0

56.9 N {5.8 kg}

–

45.1 N {4.6 kg}

2

Load check valve spring

20.9

13.2

9.3±4.9 N {0.95±0.5 kg}

–

7.8 N {0.8 kg}

3

Demand spool return spring

75.2

68.5

136.3 N {13.9 kg}

–

111.8 N {11.4 kg}

4

Relief valve spring

24.0

22.19

182.4 N {18.6 kg}

–

145.1 N {14.8 kg}

5

Check valve return spring

21.6

17.0

2.3N {0.23 kg}

–

1.8 N {0.18 kg}

40-26

Replace

WF550-3 / WF550T-3


Steering cylinder mount

Steering cylinder mount Machine body shows WF550-3.

Unit: mm No.

Check item

Criteria Tolerance

1

Clearance between mounting pin and bushing connection of steering cylinder rod and frame

2

Clearance between mounting pin and bushing at connection of steering cylinder bottom and frame

3

Connection of steering cylinder and front frame

4

Connection of steering cylinder and rear frame

WF550-3 / WF550T-3

Remedy Standard clearance

Clearance limit

+0.200 +0.100

0.100 – 0.274

–

+0.200 +0.100

0.100 – 0.274

–

Standard size Shaft

Hole

60

0 –0.074

60

0 –0.074

Width of hinge

Standard clearance (Clearance a+b)

+0.8 70 0

74±1

2.2 – 5.0

0 -0.5

74±1

3.0 – 5.5

Width of boss

70

Replace

Max. 1.0 after adjusting shim

40-27

Brake valve


Brake valve (RIGHT)

Unit: mm No.

Check item


Standard clearance

Clearance limit

Shaft 10

–0.025 –0.075

+0.1 0

0.175 – 0.025

0.25

10

–0.025 –0.075

+0.1 0

0.175 – 0.025

0.25

Standard size 1

2

3

Clearance between pedal mount hole and bracket hole

Clearance between roller and pin

Remedy

Standard size

Tolerance

Repair limit

30

0 –0.5

29.2

Outside diameter of roller

Standard size 4

Control spring

Rpair limit

Free length

Test height

Test load

Free length

34

33.5

3.82 N {0.39 kg}

33

5

Control spring

46.3

46

11.8 N {1.2 kg}

45.3

6

Return spring

86.2

58

60.8 N {6.2 kg}

78

7

Return spring

31.5

19.5

16.7 N {1.7 kg}

28

8

Spring

17

15

69.6 N {7.1 kg}

16.2

40-28

Test load

Replace

WF550-3 / WF550T-3


Brake valve

(LEFT)

Unit: mm No.

Check item


Standard clearance

Clearance limit

Shaft 10

–0.025 –0.075

+0.1 0

0.175 – 0.025

0.25

10

–0.025 –0.075

+0.1 0

0.175 – 0.025

0.25

Standard size 1

Clearance between pedal mount hole and bracket hole

2

Clearance between roller and pin

3

Outside diameter of roller

Remedy

Standard size

Tolerance

Repair limit

30

0 –0.5

29.2

Standard size 4

Control spring

Rpair limit

Free length

Test height

Test load

Free length

34

33.5

3.82 N {0.39 kg}

33

5

Control spring

46.3

46

11.8 N {1.2 kg}

45.3

6

Return spring

86.2

58

60.8 N {6.2 kg}

78

7

Return spring

31.5

19.5

16.7 N {1.7 kg}

28

WF550-3 / WF550T-3

Replace

Test load

40-29

Slack adjuster


Slack adjuster

Unit: mm No.

Check item


Standard clearance

Clearance limit

Shaft –0.030 –0.076

+0.074 0

0.030 – 0.150

0.25

Standard size 1

Clearance between body and piston 55

Standard size 2

3

40-30

Slack adjuster spring

Spring

Remedy

Repair limit

Free length

Test height

Test load

198

38

43.2 N {4.4 kg}

39.2

33

66.7 N {6.8 kg}

Free length

Replace

Test load

WF550-3 / WF550T-3


Brake

Brake

Unit: mm No.

Check item

Criteria

Remedy

Standard size 1

2

Return spring

Rpair limit

Free length

Installed height

Installed load

Free length

Installed load

80.2

69.9

600.2 N {61.2 kg}

72.2

539.4 N {55 kg}

Standard size

Tolerance

Repair limit

2.3

±0.08

2.0

Thickness of plate

3

Thickness of disc

3.8

±0.1

3.5

4

Overall assembly thickness of plates, discs

51.1

±1.52

46.0

5

Wear of piston seal contact surface

420

+0.097 0

–

6

Wear of piston seal contact surface

383

+0.089 0

–

7

Backlash between outer gear and plate

0.21 – 0.65

8

Backlash between inner gear and disc

0.31 – 0.74

WF550-3 / WF550T-3

Replace

40-31

Parking brake


Parking brake

Unit: mm No.

Check item

Criteria

Remedy

Standard size 1

Parking brake spring (outside)

2

Parking brake spring (inside)

3

Separate plate

4

5

40-32

Brake disc

Repair limit

Free length

Installed height

Installed load

Free length

Installed load

77.7

54.0

1,424±22 N {145.2±2.2 kg}

69.9

1,258 N {128.3 kg}

77.8

54.0

535±5.3 N {54.6±5.4 kg}

70.0

482 N {49.1 kg}

Standard size

Tolerance

Repair limit

Thickness

4.0

±0.05

3.9

Distortion

–

0.15

0.6

Thickness

3.2

±0.1

2.77

Depth of lining groove

0.45

+0.175 0

0.235

Thickness of lining

0.7

+0.075

–

736 N {75 kg} (Height: 3.2 mm)

±216 N {±22 kg}

468 N {47.7 kg} (Height: 3.2 mm)

Load of wave spring

Replace

WF550-3 / WF550T-3


Hydraulik pump

Hydraulik pump WF550T-3 SAR(3)-080

Unit: mm No.

1


2


3


4


–

Discharge EO10-CD 45 – 55°C


Clearance limit

0.10 – 0.15

0.19

0.06 – 0.149

0.20

Replace

0


WF550-3 / WF550T-3

Remedy

Discharge pressure MPa {kg/cm2} 20.6 {210}



184

170

–

40-33

Hydraulik pump


WF550-3 SAR(4)-160

Unit: mm No.

1


2


3


4


–



Clearance limit

0.11 – 0.16

0.19

0.06 – 0.140

0.20

Replace

0


40-34

Remedy

Discharge pressure MPa {kg/cm2} 20.6 {210}



328

303

–

WF550-3 / WF550T-3


Switch, PPC pump

Switch, PPC pump SAR(3)-63 + SAR(1)-28

Unit: mm No.

1

2

3

4

Check item

Clearance between gear case and side plate gear Clearance between inside diameter of plain bearing and outside diameter of gear shaft



Criteria Model

Standard clearance

Clearance limit

SAR(3)-63

0.10 – 0.15

0.19

SAR(1)-28

0.10 – 0.15

0.19

SAR(3)-63

0.06 – 0.149

0.20

SAR(1)-28

0.064 – 0.119

0.20

Model

Standard size

Tolerance

Repair limit

SAR(3)-63

10

0 –0.5

–

SAR(1)-28

10

0 –0.5

–

SAR(3)-63

6.9 – 11.8 Nm {0.7 – 1.2 kgm}

SAR(1)-28

2.0 – 4.9 Nm {0.2 – 0.5 kgm}

Model –


WF550-3 / WF550T-3

Remedy

Revolution (rpm)

Discharge pressure MPa {kg/cm2}



SAR(3)-63

2,500

20.6 (210)

145

134

SAR(1)-28

2,500

3.7 {3.8}

67

60

Replace

–

40-35

PPC valve


PPC valve WF550T-3

Unit: mm No.

Check item Centering spring (Tilt L.H.,lift)

1

2 3

40-36

Centering spring (Tilt R.H.,lift) Metering spring

Criteria

Remedy

Standard size Free length x O.D.

Repair limit

Installed length

Installed load

52.8 × 12.3

Free length

Installed load

36.0

29.4 N {3.0 kg}

–

23.5 N {2.4 kg}

52.8 × 12.3

36.0

39.2 N {4.0 kg}

–

31.4 N {3.2 kg}

31.4 × 7.4

29.4

16.7 N {1.7 kg}

–

13.7 N {1.4 kg}

Replace spring if damaged or deformed

WF550-3 / WF550T-3


PPC valve

WF550-3

Unit: mm No.

Check item

Criteria

Remedy

Standard size 1

Centering spring (bucket DUMP, boom LOWER)

Free length x O.D.

Repair limit

Installed length

Installed load

52.8 × 12.3

Free length

Installed load

36.0

29.4 N {3.0 kg}

–

23.5 N {2.4 kg}

2

Centering spring (bucket TILT, boom RAISE)

52.8 × 12.3

36.0

39.2 N {4.0 kg}

–

31.4 N {3.2 kg}

3

Metering spring

31.4 × 7.4

29.4

16.7 N {1.7 kg}

–

13.7 N {1.4 kg}

WF550-3 / WF550T-3

Replace spring if damaged or deformed

40-37

Main control valve


Main control valve WF550T-3

40-38

WF550-3 / WF550T-3


Main control valve

Unit: mm No.

Check item

Criteria

Remedy

Standard size 1

Spool return spring (tilt)

Repair limit

Free length x O.D.

Installed length

Installed load

Free length

Installed load

54.8 × 34

53.5

125 N {12.7 kg}

–

–

2

Spool return spring (tilt, lift)

54.8 × 33.7

52.5

235.5 N {24 kg}

–

–

3

Spool return spring (tilt, lift)

30.7 × 32.5

26.8

235.5 N {24 kg}

–

–

4

Spool return spring (lift)

55.3 × 16.9

40

233 N {23.8 kg}

–

–

5

Spool return spring (lift)

86.8 × 34.7

83.5

208 N {21.2 kg}

–

–

6

Main valve spring

39.5 × 11.2

23.2

33 N {3.4 kg}

–

–

7

Check valve spring

32.6 × 10.9

24.5

44 N {4.5 kg}

–

–

8


27.9 × 13

19

7N {0.7 kg}

–

–

9

Poppet spring

49.3 × 12.8

41.9

259 N {26.4 kg}

–

–

WF550-3 / WF550T-3

Replace

40-39

Main control valve


WF550-3

40-40

WF550-3 / WF550T-3


Main control valve

Unit: mm No.

Check item

Criteria

Remedy

Standard size 1

Bucket spool return spring (Large)

Repair limit

Free length

Installed length

Installed load

Free length

Installed load

64.4

62.2

190 N {19.4 kg}

–

152 N {15.5 kg}

2

Bucket spool return spring (Small)

18.6

14.9

112.8 N {11.5 kg}

–

90 N {9.2 kg}

3

Boom spool return spring (Large)

64.4

62.7

149 N {15.2 kg}

–

119.6 N {12.2 kg}

4

Boom spool return spring (Small)

18.6

15.2

104 N {10.6 kg}

–

83.4 N {8.5 kg}

5

Boom spool return spring (Large)

89.2

82.0

616 N {62.8 kg}

–

554 N {56.5 kg}

6

Boom spool return spring (Small)

42.0

42.0

0

–

–

7

Bucket spool return spring (Large)

82.4

82.0

182.4 N {18.6 kg}

–

163.8 N {16.7 kg}

8

Bucket spool return spring (Small)

42.0

42.0

0

–

–

9

Main valve spring

52.3

38.0

86.3 N {8.8 kg}

–

68.6 N {7.0 kg}

10

Check valve spring

78.2

52.0

18.8 N {1.92 kg}

–

14.7 N {1.5 kg}

11

Suction valve spring of safety valve

27.9

18.0

6.9 N {0.70 kg}

–

5.9 N {0.6 kg}

12


27.9

18.0

6.9 N {0.70 kg}

–

5.9 N {0.6 kg}

13

Float selector valve spring

53.0

42.1

137 N {14.0 kg}

–

123.6 N {12.6 kg}

14

Unloader valve spring

82.7

47.0

49 N {5.0 kg}

–

39 N {4.0 kg}

15

Relief valve poppet spring

49.3

43.3

209.9 N {21.4 kg}

–

167.7 N {17.1 kg}

WF550-3 / WF550T-3

Replace

40-41

Cut-off valve


Cut-off valve WF550-3

Unit: mm No.

Check item

Criteria

Remedy

Standard size 1

2

40-42

Unload valve spring

Check valve spring

Repair limit

Free length

Installed length

Installed load

Free length

Installed load

36.95

3.0

35.3 N {3.6 kg}

–

28.4 N {2.9 kg}

33

2.0

1.7 N {0.17 kg}

–

1.4 N {0.14 kg}

Replace

WF550-3 / WF550T-3


Cut-off valve


WF550-3 / WF550T-3

40-43

Hydraulic cylinders


Hydraulic cylinders WF550T-3 Steering cylinder

Width across flats: 60 mm

Lift cylinder

40-44

WF550-3 / WF550T-3


Hydraulic cylinders

Unit: mm No.

1

2

3

4

Check item

Clearance between rod and bushing

Clearance between piston rod mounting pin and diameter of hole

Clearance between cylinder bottom mounting pin and bushing

Cylinder bore

WF550-3 / WF550T-3

Criteria Name of cylinder

Standard size

Steering

Remedy

Tolerance Shaft

Hole

Standard clearance

55

–0.030 –0.076

+0.151 +0.006

0.036 – 0.227

0.327

Lift

80

–0.100 –0.174

+0.271 +0.061

0.161 – 0.445

0.469

Steering

60

0 –0.074

+0.174 +0.100

0.100 – 0.248

1.0

Lift

60

–

+0.046 0

–

–

Steering

60

0 –0.074

+0.174 +0.100

0.100 – 0.248

1.0

Lift

60

–

+0.046 0

–

–

Standard size

Tolerance

Steering

110

+0.15 0

Lift

140

+0.25 0

Clearancelimit

Replace

Repair limit

40-45

Hydraulic cylinders


WF550-3 Steering cylinder

Width across flats: 60 mm

Boom cylinder

Bucket cylinder

40-46

WF550-3 / WF550T-3


Hydraulic cylinders

Unit: mm No.

1

2

3

4

Check item

Clearance between rod and bushing

Clearance between piston rod mounting pin and diameter of hole

Clearance between cylinder bottom mounting pin and bushing

Criteria Name of cylinder

Standard size

Steering

Tolerance Shaft

Hole

Standard clearance

55

–0.030 –0.076

+0.151 +0.006

0.036 – 0.227

0.327

Boom

110

–0.036 –0.090

+0.274 +0.060

0.096 – 0.364

0.469

Bucket

120

–0.043 –0.106

+0.203 +0.048

0.091 – 0309

0.469

Steering

60

0 –0.074

+0.174 +0.100

0.100 – 0.248

1.0

Boom

120

–

+0.1 0

–

–

Bucket

120

–

+0.307 +0.220

–

–

Steering

60

0 –0.074

+0.174 +0.100

0.100 – 0.248

1.0

Boom

120

–

+0.307 +0.220

–

–

Bucket

120

–

+0.307 +0.220

–

–

Standard size

Tolerance

Steering

110

+0.15 0

Boom

200

+0.2 0

Bucket

225

+0.2 0

Cylinder bore

WF550-3 / WF550T-3

Remedy Clearancelimit

Replace

Repair limit

40-47

Work equipment linkage


Work equipment linkage WF550T-3

40-48

WF550-3 / WF550T-3



Unit: mm No.

Check item


Hole

Standard clearance

60

–0.030 –0.076

+0.20 +0.30

0.124 – 0.270

1.0

120

–0.043 –0.0106

–0.395 –0.295

0.338 – 0.4056

1.0

Standard size 1

2

Clearance between pin and lift cylinder rod at connection

Clearance between pin and bushing at connection of brade and frame

Width of boss

3

Connection of brade and frame

WF550-3 / WF550T-3

Remedy

150 ± 3

Width of hinge

Clearance limit

Standard clearance

Replace replace if there is scuffing on pin

Adjust with shims so that clearance is less than 1.5 mm on both left and right

40-49



WF550-3

40-50

WF550-3 / WF550T-3



Unit: mm No.

Check item

1

Clearance between pin and bushing at both ends of bukket link

Criteria Tolerance

Clearance limit

Hole

Standard clearance

1.0

Standard size Shaft 110

–0.036 –0.090

Remedy

2

Clearance between pin and bushing at joint of boom and bucket

110

–0.036 –0.090

3

Clearance between pin and bushing at joint of boom and frame

120

–0.036 –0.090

+0.307 +0.220

0.256 – 0.397

4

Clearance between pin and bushing at joint of bucket cylinder bottom and frame

120

–0.036 –0.090

+0.307 +0.220

0.256 – 0.397

1.0

5

Clearance between pin and bushing at joint of bucket cylinder rod and bellcrank

120

–0.036 –0.090

+0.307 +0.220

0.256 – 0.397

1.0

6

Clearance between pin and bushing at joint of bellcrank and boom

140

–0.043 –0.106

+0.395 +0.295

0.338 – 0.501

1.0

7

Clearance between pin and bushing at joint of boom cylinder bottom and frame

120

–0.036 –0.090

+0.307 +0.220

0.256 – 0.397

1.0

8

Clearance between pin and bushing at joint of boom cylinder rod and boom

120

–0.036 –0.090

+0.307 +0.220

0.256 – 0.397

1.0

9

Joint of bucket cylinder and frame

Width between bosses

Width of hinge

Standard clearance (Clearance a + b)

143

140

3.0

150

3.0

10

Joint of boom and frame

153

11

Joint of boom and bucket

180

12

Joint of bucket link and bucket

145

13

Joint of bellcrank and bucket link

144

142

2.0

14

Joint of bellcrank and boom

240

237

3.0

15

Joint of bellcrank and bucket cylinder

143

140

3.0

16

Joint of boom cylinder and boom

125

122

3.0

17

Joint of boom cylinder and frame

123

120

3.0

WF550-3 / WF550T-3

Replace also if other parts are biting into pin

Insert shims on both sides to make clearance on both left and right sides less than 1.5 mm

40-51

Bucket positioner and boom kick-out


Bucket positioner and boom kick-out WF550-3

Unit: mm No.

Check item

Criteria

1

Clearance of bucket positioner switch

3–5

2

Clearance of boom kick-out switch

3–5

Remedy

Adjust

40-52

WF550-3 / WF550T-3


ROPS cab

ROPS cab

WF550-3 / WF550T-3

40-53

ROPS cab



40-54

WF550-3 / WF550T-3

90 OTHERS Hydraulic circuit diagram for power train . . 90-2 Brake circuit diagram . . . . . . . . . . . . . . . . . . 90-4 Electric circuit for cooling fan . . . . . . . . . . . 90-6 Work equipment hydraulic circuit diagram (WF550T-3) . . . . . . . . . . . . . . . . . . . . . . . . . . 90-51 Work equipment hydraulic circuit diagram (WF550-3) . . . . . . . . . . . . . . . . . . . . . . . . . . . 90-53 Electric circuit diagram (1/4) . . . . . . . . . . . 90-101 Electric circuit diagram (2/4) . . . . . . . . . . . 90-103 Electric circuit diagram (3/4) . . . . . . . . . . . 90-105 Electric circuit diagram (4/4) . . . . . . . . . . . 90-107

WF550-3 / WF550T-3

90-1

Hydraulic circuit diagram for power train

OTHERS


90-2

WF550-3 / WF550T-3

OTHERS


1

Transmission case

16

FORWARD ECMV

2

Strainer

17

REVERSE ECMV

3


18

3rd ECMV

4

Torque converter oil filter

19

4th ECMV

5

Main relief valve

20

2nd ECMV

6

Torque converter relief valve

21

1st ECMV

7

Torque converter

22

Flow detector valve

8

Oil cooler

23

Pressure control valve

9

Transmission lubrication

24

FORWARD clutch

10


25

REVERSE clutch

11

Pilot oil filter

26

3rd clutch

12

Parking brake solenoid valve

27

4nd clutch

13

Parking brake emergency release valve

28

2nd clutch

14

Accumulator

29

1st clutch

15

Parking brake

WF550-3 / WF550T-3

90-3

Brake circuit diagram

OTHERS


From T / M valve pilot circuit

Cut - in Cut - out

To PPC valve

90-4

WF550-3 / WF550T-3

OTHERS

1.


Hydraulic pump

10. Transmission cut-off switch

1A. Switch pump

11. Right brake valve

1B. PPC and brake pump

12. Pilot lamp switch

2.

Strainer

13. Rear slack adjuster

3.

Accumulator charge valve

14. Front slack adjuster

3A. Safety relief valve

15. Emergency parking brake valve

3B. PPC relief valve

15A. Parking brake emergency release solenoid

3C. Filter

16. Parking brake emergency release switch

4.

Check valve

17. Parking brake

5.

Low pressure switch

18. Parking brake pilot lamp switch

6.

Rear brake accumulator

19. Parking brake solenoid

7.

Front brake accumulator

20. Parking brake valve

8.


21. Transmission pump

9.

Left brake valve

22. Parking brake switch

WF550-3 / WF550T-3

90-5

90-6

FLASHER UNIT RELAY

TIMER RELAY

REVOLVING DIRECTION RELAY

FLASHER UNIT

REVERSE INDICATOR LAMP DIODE (FLASHES)

AUTO / MANUAL SELECTOR SWITCH

FORWARD / REVERSE SELECTOR SWITCH TIMER-3

TIMER-2

FAN DIRECTION CONTROL VALVE

TIMER-1

FUSE BOX POWER SUPPLY (+24V)

Electric circuit for cooling fan OTHERS

Electric circuit for cooling fan

WF550-3 / WF550T-3

Work equipment hydraulic circuit diagram (WF550T-3)

WF550-3 / WF550T-3

90-51

90-52

WF550-3 / WF550T-3

Work equipment hydraulic circuit diagram (WF550-3)

WF550-3 / WF550T-3

90-53

90-54

WF550-3 / WF550T-3

Electric circuit diagram (1/4)

WF550-3 / WF550T-3

90-101


WF550-3 / WF550T-3

90-103


WF550-3 / WF550T-3

90-105


WF550-3 / WF550T-3

90-107

VEBM090100_WF550-3_T-3

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