Manual de Sistema Hidraulico D9R 2.pdf

SENR5389-02 January 2001

Systems Operation Testing and Adjusting D9R Track-T rack-Type Tractor ractor Hydraulic System 7TL1-Up (Machine)

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Important Safety Information Most accidents that involve product operation, maintenance and repair are caused by failure to observe basic safety rules or precautions. An accident can often be avoided by recognizing potentially hazardous situations before an accident occurs. A person must be alert to potential hazards. This person should also have the necessary training, skills and tools to perform these functions properly.

Improper operation, lubrication, maintenance or repair of this product can be dangerous and could result in injury or death. Do not operate or perform any lubrication, maintenance or repair on this product, until you have read and understood the operation, lubrication, maintenance and repair information. Safety precautions and warnings are provided in this manual and on the product. If these hazard warnings are not heeded, bodily injury or death could occur to you or to other persons. The hazards are identified by the “Safety Alert Symbol” and followed by a “Signal Word” such as “DANGER”, “WARNING” or “CAUTION”. The Safety Alert “WARNING” label is shown below.

The meaning of this safety alert symbol is as follows:

Attention! Become Alert! Your Safety is Involved. The message that appears under the warning explains the hazard and can be either written or pictorially presented. Operations that may cause product damage are identified by “NOTICE” labels on the product and in this publication. publication.

Caterpillar cannot anticipate every possible circumstance that might involve a potential hazard. The warnings in this publication and on the product are, therefore, not all inclusive. If a tool, procedure, work method or operating technique that is not specifically recommended by Caterpillar is used, you must satisfy yourself that it is safe for you and for others. You should also ensure that the product product will not be damaged damaged or be made unsafe unsafe by the operation, operation, lubrication, lubrication, maintenance maintenance or repair procedures that you choose. The information, specifications, and illustrations in this publication are on the basis of information that was available at the time that the publication was written. The specifications, torques, pressures, measurements, adjustments, illustrations, and other items can change at any time. These changes can affect the service that is given to the product. Obtain the complete and most current information before you start any job. Caterpillar dealers have the most current information available. For a list of the most current publication form numbers available, see the Service Manual Contents Microfiche, REG1139F.

When When replac replaceme ement nt parts parts are requir required ed for for this this product Caterpillar recommends using Caterpillar replac replaceme ement nt parts parts or parts parts with with equiva equivalen lentt specifications including, but not limited to, physical dimensions, type, strength and material. Failure to heed this warning can lead to premature failures, product damage, personal injury or death.



























3 Table of Contents

Table of Contents Systems Operation Section General Information ..................... ............................... .................... ................. ....... 4 Hydraulic Oil Cooler .................... .............................. .................... ................. ....... 4 Hydraulic Pump - Piston .................... .............................. .................... .......... 5 Implement Hydraulic System ................................ 14 Implement Control Valve Valve .................... .............................. .................. ........ 15 Inlet Manifold .................... .............................. ..................... ..................... ............... ..... 16 Main Relief Valve Valve ..................... ............................... .................... .................. ........ 16 Charging Valve .................... .............................. .................... ..................... ............. .. 17 Steering Pump .................... .............................. .................... ..................... ............. .. 18 Steering Pilot Valve ......................... ................................... ..................... ............. 27 Steering Motor .................... .............................. .................... ..................... ............. .. 28 Oil Filter (Steering Charge Loop) .......................... 29 Bulldozer Lift Control Valve Valve ..................... ............................... ............. ... 30 Bulldozer Tilt Control Valve Valve ..................... ............................... ............. ... 33 Dual Tilt Control Valve Valve .................... .............................. .................... ............ 36 Ripper Lift Control Valve Valve .................... .............................. .................. ........ 39 Ripper Tip Control Valve Valve .................... .............................. .................. ........ 41 Pin Puller Hydraulic System .................... .............................. ............ .. 44 Pressure Control Valve Valve ..................... ............................... ................... ......... 45 Quick-Drop Valve Valve .................... .............................. .................... .................... .......... 47

Testing and Adjusting Section Testing and Adjusting Testing and Adjusting ............................ ....................................... ................ ..... 52

Index Section Index .................... .............................. .................... .................... .................... ................... ......... 92



























4 Systems Systems Operation Operation Section Section

Systems Operation Section

Oil Cooler Bypass Valve

i01021015

General Information SMCS Code: 5050 The implement system and the differential steering system have separate pumps. The separate pumps provide a better performance match for combined and simultaneous operation. The steering circuit is a closed loop hydraulic system that has a variable displacement axial piston pump with over-the-center capability. The implement hydraulic system is a load sensing, sensing, pressure pressure compensated compensated system. system. Also, the system has a variable displacement axial piston pump. The machine has following features: pilot operated steering steering control, steering motor with internal flushing flushing valve, three-section hydraulic pump, priority and makeup valve, and combined parking and service brake. i01033715

Hydraulic Oil Cooler SMCS Code: 1374 The hydraulic oil cooler is an oil-to-air design. The cooler is located in the top of the radiator. After the charge pump oil is cooled, the oil is sent to the filter. The oil then flows to the steering pump. The cooler dissipates the heat from the implement and steering systems in order to prevent overheating.

Illustration 1

g00532404

Oil Cooler Bypass Valve (1) Port (inlet from charge pump) (2) Blocked port (3) Bypass valve (4) Port (outlet to filter base) (5) Port (outlet to oil cooler)

The steering loop charge pump takes oil from the tank and the pump sends the oil to inlet port (1). If the oil temperature is below 57 C (135 F), most of the oil is sent through bypass valve (3) to outlet port (4). Then, the oil flows to the steering pump charge circuit. When the oil temperature is 66 C (150 F), bypass valve (3) is completely closed. The oil flows through outlet port (5) to the oil cooler. The oil flows to the steering motor case and steering pump case for cooling purposes.



























5 Systems Operation Section

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Hydraulic Pump - Piston SMCS Code: 5070

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Illustration 2 Variable Displacement Piston Pump and Compensator Valve (1) Spring (2) Spring (3) Compensator valve (4) Actuator piston (5) Shoe plate (6) Drive shaft (7) Swashplate

(8) Piston shoe (9) Piston (10) Bias piston (11) Bias spring (12) Cylinder barrel (13) Pressure compensator spool (14) Flow compensator spool




























The hydraulic pump has two control pistons:bias piston (10) and actuator piston (4). The bias piston is used to upstroke the pump. The piston is spring loaded by spring (11) and the piston is assisted by pump discharge pressure. Actuator piston (4) is used to destroke the pump and the piston has a larger area than the bias piston. Flow compensator spool (14) and pressure compensator spool (13) change the pump displacement by regulating the pressure in actuator piston (4). The larger area of actuator piston (4) enables the piston to overcome bias piston (10) and spring (11) in order to destroke the pump when compensator valve (3) applies pump discharge pressure to the piston. Pump outlet pressure is maintained at about 2100 kPa (305 psi) above work port pressure. Also, the compensator valve has a pressure limiting ability. The pressure limiting ability prevents overloads of the pump and system. When work port pressure goes over 26200 kPa (3800 psi), pressure compensator spool (13) overrides flow compensator spool (14) and lowers pump output. The action starts at about 690 kPa (100 psi) below the maximum pressure setting. The following schematics show the pump and the compensator valve under different conditions in the hydraulic hydraulic system. system.






























Upstroking

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Illustration 3 Pump and Compensator Operation (Upstroke) (1) Spring (2) Spring (3) Line to control valve (4) Actuator piston

(8) Case drain (9) Passage (10) Passage (11) Passage

(15) Cavity (16) Signal line from control valve (AA) High pressure oil (EE) Pilot oil




























Upstroking means that the pump is increasing the displacement. Upstroking occurs when the signal pressure increases due to an increased load pressure. The highest resolved signal pressure from the implement valve flows through line (16). The highest resolved signal pressure then fills cavity (15). Signal pressure plus the force of spring (1) will move spool (14) downward. Spool (14) blocks the flow of supply oil to actuator piston (4). When flow compensator spool (14) moves downward, the oil under the actuator piston can drain past flow compensator spool (14). The oil flows through the pressure compensator spring cavity, and out through passage (10) to case drain (8). Supply oil flows through passage (9) to bias piston (6). The oil combines with the force of bias spring (13). The combined force moves the swashplate toward the maximum angle. Thus, pump output increases. The pump output pressure increases until the pressure in passage (11) moves spool (14) up to the metering position. The pump pressure is greater than the combined force of spring (1) and the signal pressure in cavity (15). Spool (14) moves up. Pressure is sent to actuator piston (4). The force of the actuator piston that is moving swashplate (5) closer to the minimum angle is greater than the force of the bias piston and of the bias spring that is moving swashplate (5) closer to the maximum angle. The angle of swashplate (5) decreases. Pump output decreases. When pump pressure has decreased, the signal pressure in cavity (15) and the spring force in cavity (15) move spool (14) downward. The oil pressure that is behind actuator piston (4) flows back to the case drain. Bias piston (6) and spring (7) force the angle of swashplate (5) to increase.




























Destroking

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Illustration 5 Pump and Compensator Operation (Destroke) (1) Spring (2) Spring (3) Line to control valve (4) Actuator piston

(8) Case drain (9) Passage (10) Passage (11) Passage

(15) Cavity (16) Signal line from control valve (AA) High pressure oil (FF) Reduced pilot oil




























Low Pressure Standby

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Illustration 6 Pump and Compensator Operation (Low Pressure Standby) (1) Spring (2) Spring (3) Line to control valve (4) Actuator piston

(7) Bias spring (8) Case drain (9) Passage (10) Passage

(13) Pressure compensator spool (14) Flow compensator spool (15) Cavity (16) Signal line from control valve




























Before the engine is started, bias spring (7) holds swashplate (5) at the maximum angle. As the pump begins to turn, the pressure builds up in the system because of the closed center implement valves. The pressure in passage (11) is felt at the bottom of the pressure compensator and of the flow compensator spools. As the pressure increases, the pressure pushes the flow compensator spool against spring (1). When system pressure becomes greater than 2100 kPa (305 psi), spool (14) moves up enough to open up a passage for pressure oil to the back of actuator piston (4). This causes the actuator piston to move to the right. The actuator piston compresses bias spring (7) and the actuator piston moves the swashplate toward the minimum angle. The actuator piston continues to move to the right until the actuator piston uncovers the cross-drilled passage of the actuator piston rod. This allows the oil to drain to the case. Pump output is not good enough to make up for the system leakage and for the additional leakage through the cross-drilled hole. The piston moves to the left until only part of the cross-drilled hole is open to the case. This further increases oil pressure behind the actuator piston. Also, this limits the maximum travel of the piston to the right. The pump output is good enough to make up for the system leakage and for the leakage to the pump case through the cross-drilled hole. Also, the pump maintains the system pressure at a maximum of 3600 kPa (520 psi). The pump is at low pressure standby. The pressure is different from the margin pressure because of system leakage and because of the cross-drilled hole in the actuator piston rod. The flow compensator spool must remain open and the spool must move up higher against spring (1) in order to provide enough flow to the back side of the actuator piston to make up the leakage through

Note: Low pressure standby is not adjustable. The pressure varies on different machines. The pressure also varies in the same pump as the system leakage or the pump leakage increases. As leakage increases, the pump upstrokes slightly in order to compensate for the leakage, and the actuator piston covers more of the cross-drilled hole. As the actuator piston covers more of the cross-drilled hole, low pressure standby drops toward margin pressure. When the piston completely covers the cross-drilled hole, low pressure standby will equal margin pressure.






























High Pressure Stall (Cutoff)




























When the hydraulic system stalls under load or when the cylinders reach the end of the stroke, system pressure increases. The signal pressure in line (16) and cavity (15) becomes equal to the pump output pressure. Spring (1) keeps spool (14) shifted downward. When system pressure reaches 26200 kPa (3800 psi) in passage (11), the upward force on pressure compensator spool (13) compresses spring (2). The pressure compensator spool (13) moves upward. Supply oil flows through passage (12) to actuator piston (4). The pressure that is felt on the actuator piston destrokes the pump. Pump output (flow) decreases while system pressure is limited to 26200 kPa (3800 psi). At 26200 kPa (3800 psi), the swashplate angle is sufficient to make up for the system leakage. Also, the pump maintains the maximum pressure. If a control lever is moved to HOLD during a high pressure stall, the signal pressure in cavity (15) flows through passage (16). The signal pressure flows to the control valve, and then to the tank. System pressure begins to bleed down. At approximately 25100 kPa (3640 psi), spring (2) moves pressure compensator spool (13) downward. The system pressure in passage (11) acts against the force of spring (1) to move flow compensator spool (14) upward. Supply oil flows past flow compensator spool (14)




























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Implement Hydraulic System SMCS Code: 5050




























The hydraulic pump is a variable displacement piston pump that is load sensing and pressure compensated. The pump provides oil for all implement circuits. When the implements are not active, the pump is destroked. The pump will make up any system leakage and the pump will maintain a pressure of approximately 3600 kPa (520 psi) maximum to the control valves. If an implement circuit is activated, the load sensing valve senses the load increase through the valve bank signal network and the valve upstrokes the pump. The pump upstrokes until the pump pressure is approximately 2100 kPa (305 psi) over the load signal from the control valve. The maximum pressure in the circuit is controlled by the cutoff spool in the compensator valve. When the pressure in the implement circuit reaches approximately 26200 kPa (3800 psi), the pump destrokes in order to maintain the pressure until the system pressure decreases. A main relief valve is in the system in order to limit pressure increases over approximately 29600 kPa (4290 psi). The implement control valve bank has an inlet manifold, a end cover, and four control sections. The sections are the following valves: bulldozer lift control valve, bulldozer tilt control valve, ripper lift control valve, and ripper tilt control valve. The main relief valve and the charging valve are

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Implement Control Valve SMCS Code: 5051; 5115; 5123; 5136; 5140




























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i01023384

Inlet Manifold

Main Relief Valve

SMCS Code: 1058

SMCS Code: 5069; 5117

Illustration 11

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(1) Inlet passage (2) Dump valve (3) Spring (4) Retainer (5) Nut (6) Drain passage (7) Drain passage

The main relief valve is in front of all other valves in the implement hydraulic system. The valve is a






























i01023397

Charging Valve SMCS Code: 5051

The second source of signal pressure to the charging valve is from cylinder return oil through passage (7) and check valve (8). When the signal pressure in passage (9) is below the return oil pressure in passage (7), check valve (8) will open. The oil flows to chamber (3) in order to move valve (4) upward. The pressure that is required in order to move valve (4) is controlled by the pressure that is needed for the makeup valve. Also, the pressure is controlled by the oil line restrictions in the hydraulic circuit. Orifice (2) is used in the circuit in order to keep the return oil in passage (7) from going to the drain. The orifice controls the loss of pressure so that the return oil pressure to the charging valve is constant.




























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Steering Pump SMCS Code: 4306-QP























































Charge Pump Relief Valve

Illustration 16 Charge Pump Relief Valve

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Pressure Compensator Valve






























Crossover Relief and Makeup Valves

Charge Pump




























Pump Control Valve




























Resolved loop pressure is in passage (8). The oil flows into passage (8) through passages that are not shown, and from the ball resolver that is located in the pump head. Oil from passage (8) flows into passage (7) by passing through the holes in sleeve (4) that have been uncovered by spool (6). The oil

As sleeve (4) moves to the left, some oil in chamber (2) is forced through orifice (1) and the oil drains through the pilot valve.

Cutoff Operation During Left Steering Steering




























The oil that is flowing into cavity (2) flows out of orifice (1). Orifice (1) causes the pressure to increases in cavity (2). The higher pressure in cavity (2) moves sleeve (4) back to the near neutral position. This causes the swashplate to return to the near neutral position. The swashplate will maintain a




























Null is adjusted by screw (9). When adjustment screw (9) is turned, bracket (8) is rotated slightly. The bracket is rotated around the pin and spacer (10). The location of pivot pin (3) is moved as bracket (8) is rotated. Bracket (8) is held firmly against adjustment screw (9) by spring (7).



































































































































































































































































































































































































































































































































































































































































































































































































62 Testing and Adjusting Section

Problem Checklist

d. The plug that is in the end of the control valve spool has a failed seal.

1. There is leakage through a hole in a hydraulic hose or fitting.

4. The pump control is worn.

2. Leakage past the cylinder rod seals.

5. The pump is not at full stroke.

3. There is leakage past the shaft seal for the implement pump.

6. The diameter of the hoses or the fittings is incorrect.

Cycle time of one implement is too slow.

The implement droops when the control lever is moved from HOLD to LIFT.

Problem Checklist Problem Checklist 1. The implement valve spool is not fully shifted. 2. The lever linkage or lever travel is restricted. 3. The wrong control valve for the implement is installed in the valve bank.

1. The load check valve is not closing. The problem is caused by the following causes: a. The spring is weak or broken. b. The valve has dirt or debris.

4. The control valve is worn. c. There is a worn seat. 5. There is debris in the ball resolver network. The debris may be caused by the following causes: a. The flow control sleeve behind the flow control spring has failed seals or the sleeve is improperly adjusted. b. The plug in the end of a control valve spool has a failed seal or the plug is loose.

There is too much implement drift. Problem Checklist 1. The valve spool in the control valve is not correctly centered. The problem is caused by the following causes: a. There is a broken spring.

c. The shuttle valve is stuck open or the valve has failed seals. 6. When the bulldozer will not raise, the quick-drop valve may be energized or the valve is stuck. All implement cycle times are too slow. Problem Checklist 1. The air purge valve on the controls for the implement pump is open.

b. There is a sticky valve spool. c. There is a misadjusted linkage. 2. There is leakage around the seals on the piston or the piston is loose on the cylinder rod. 3. There is leakage past the makeup valve or the makeup valve seals have failed. 4. The quick-drop valve or the end stroke bypass valves are leaking.

2. The margin pressure setting is too low. 5. The control valve has too much wear. 3. There is a blockage or a leakage in the signal network. The problem is caused by the following causes:

One or more implement circuits are unstable. Problem Checklist

a. The signal line is plugged or the line is not



























63 Testing esting and Adjusting Adjusting Section Section

4. A damping orifice is missing in the signal hose or the orifice is missing in the signal network. Implement cycle times are too fast. Problem Checklist 1. Margin pressure in the compensator valve is set too high.

Problem Checklist 1. The wrong control valve is installed in the valve bank. 2. The flow control valve is worn or the valve is improperly adjusted. The pump does not return return to standby standby pressure after the implement implement lever is returned returned to NEUTRAL. NEUTRAL.

2. The flow control valve(s) failed or there is a incorrect spool.

Problem Checklist

Any implement implement moves moves with the control lever in the HOLD position. position.

1. The control lever has interference and the lever does not return to HOLD position.

Problem Checklist

2. The hydraulic pump or the compensator valve is worn.

1. The control valve and the valve spool have a large amount of wear. 2. The seals in the cylinder piston have failed or the seals are worn. 3. The load check valve is worn.

There is too little lever travel before the bulldozer quick-drop valve is activated. Problem Checklist 1. There is the wrong number of shims under the springs in quick-drop valve.

4. The control valve spool is not centered. 2. There is a weak spring in the quick-drop valve. When the blade is lowered to the ground, there is excessive pause time at ground line.

There There is too much much lev lever er tra travel vel before before the bulldo bulldozer zer quick-drop valve is activated.

Problem Checklist Problem Checklist 1. The quick-drop valve is not operating correctly. 2. The makeup valve is stuck open. 3. There is a restriction in a hose. The implement surges when the implement is first activated.

1. There is a wrong spring or too many shims in the quick-drop valve. 2. The drain hose for the quick-drop valve is blocked. 3. The orifices or the passages in the quick-drop spool are plugged with debris.

Problem Checklist 1. The slots in the control stem are not machined correctly.

4. The quick-drop spool is stuck. The quick-drop spool is jammed with debris. The quick-drop valve is not working properly.

The effort that is needed in order to move the control lever is too high. Problem Checklist 1. The lever linkage is restricted or the linkage has interference.

Problem Checklist 1. The fuse is blown. The activation switch is worn or there is a wiring problem.




























6. A electrical contact is pitted due to faulty operation of a diode.

Implement Operation Checks

There is weak hydraulics. Problem Checklist 1. The air purge valve on the controls for the implement pump is open. 2. The signal line is not connected or plugged. 3. There is a stuck resolver ball. 4. The end pressure resolver is not drained to the tank. 5. The setting for the pump cutoff pressure is low. 6. There is a broken load sensing spring or a broken pressure cutoff spring. 7. There is an improperly adjusted linkage. 8. The pump is worn. 9. There is leakage in the system. 10. The makeup valve is stuck open. 11. The main relief valve pressure setting is wrong or the relief valve is worn. The force of the bulldozer bulldozer tilt is weak. Problem Checklist 1. The pressure limiter is improperly adjusted or the limiter is worn. 2. The end stroke bypass valves are leaking. The problem is for machines with dual tilt cylinders.

Personal injury or death can result from sudden machine movement. Sudden movement of the machine can cause injury to persons on or near the machine. Prevent possible injury by performing the procedure that follows before working on the machine. Move Move the machine machine to a smooth smooth horizo horizonta ntall locati location. on. Move away away from from working working machines machines and personnel personnel and lower the buckets or implements (loader and backhoe) and stabilizers to the ground. Permit Permit only only one operator operator on the machine. machine. Keep all other personnel away from machine or in view of the operator. Engage the parking brake. Stop the engine. Move the hydraulic control levers to all positions to release the pressure in the hydraulic system. The operation checks can be used to find leakage in the system. Also, the tests can be used to find a bad valve or a bad pump. The speed of the rod movement can be used in order to check the condition of the cylinders and the condition of the pump. Raise and lower the bulldozer and the ripper several times. Operate the tilt control valve until the tilt cylinder has been fully extended and retracted several times.

1. Watch the cylinders as the cylinders are extended and retracted. Movement must be smooth and regular. 2. Listen for noise from the pump. 3. Allow the implement cylinders to travel full stroke in each direction. 4. Put each control valve in the HOLD position while the implement is off the ground. Watch for excessive cylinder rod drift.




























The speeds that are shown in the chart indicate that the circuit operation is normal.

If the cylinder speeds are incorrect follow the following following steps:

Table 1

Bulldozer Lift Cylinders Drift Tests Machines That Are Equipped With A Single Tilt Cylinder

Bulldozer Blade

Speed Test for the Bulldozer Tilt Cylinder

Time Time in Seconds

All Blades

Full tilt left to full tilt right

2.4 to 2.8

Full ull tilt ilt righ rightt to full tilt left

3.1 to 3.5

All All Blad Blades es

1. Check the hydraulic oil temperature.

Table 2

Machin Machines es That That AreEquipped AreEquipped With With A Dual Dual Tilt Tilt Cyl Cylind inder er Bulldozer Blade

Speed Test for the Bulldozer Tilt Cylinder

The drift rates change with the different conditions of the hydraulic components. Before measuring drift on the cylinder rod, the cylinders must be extended and retracted at least five times. Measure the rod drift by using the following procedure:

Time Time in Seconds

SINGLE TILT MODE All Blades

Full tilt left to full tilt right

3.1 to 3.5


Full ull tilt ilt righ rightt to full tilt left

2.4 to 2.8

2. Lift the bulldozer until the cutting edge is approximately 300 mm (12 inch) off the ground. With the lift control lever in the HOLD position, stop the engine. 3. Measure the extension of the lift cylinder rods from the lift cylinders. Record the distance that was measured. 4. Record the distance and the time. Compare the readings with the chart. Note: The drift distance in the chart is for new machines. Table 5

DUAL TILT MODE

Bulldozer Lift Cylinder Drift


Full Full tilt tilt left left to full full tilt right

3.1 to 3.5


Full Full tilt tilt righ rightt tofull tofull tilt left

2.9 to 3.3

Oil Temperature

28 to 48 C (83 to 118 F)

49 to 68 C (120 to 155 F)

69 88 (156 190

38 mm (1.5 inch)

5 minutes

2.7 minutes

1.7 minutes

PITCH MODE All All Blad Blades es

Full Full pitc pitch h bac back to full pitch out

3.5 to 3.9


Full Full pitc pitch h out out to full pitch back

2.3 to 2.7

to C to F)

Note: If excessive cylinder drift is noted, run the following tests in order to determine the cause.

Tests

Table 3

Bulldozer Blade

Speed Test for the Bulldozer Lift Cylinder

Time Time In Seconds

All Blades

Ground to full up

5.3 to 5.5

Full up to ground (Quick-drop)

.9 to 1.2

Pause at ground (Quick-drop).

1.2 to 1.7

1. Raise the front of the machine off the ground by lowering the bulldozer on level ground. Put the control lever in the HOLD position. Shut off the engine and watch the lift cylinder rods for movement. 2. Raise the front of the machine off the ground by lowering the bulldozer on level ground. Shut off the engine. Hold the lift control lever in the LOWER position. Watch the lift cylinder rods for




























4. Raise the bulldozer off the ground. Shut off the engine. Hold the lift control lever in the RAISE position. Watch the lift cylinder rods for movement. Table 6

Test Results

Most Probable Causes

Drifting occurs in tests 1 and 2.

The lift lift circui circuitt makeup makeup valv valve e (head ends) is leaking.


There is leakage between the lift valve spool and the valve body.

Drifting occurs in tests 1, 2, 3 and 4.

There is leakage between pistons and cylinders. The piston valves in the cylinders are bad. The quick-drop valve is leaking.

Tests 1. Put the bulldozer flat on the ground. Raise the front of the machine off the ground by lowering the right side of the blade. Put the tilt circuit in the HOLD position. Shut off the engine and watch the tilt cylinder rod for movement. 2. Put the bulldozer flat on the ground. Raise the front of the machine off the ground by lowering the left side of the blade. Put the tilt circuit in the HOLD position. Shut off the engine and watch the tilt cylinder rod for movement. Table 8

Test Results



The lift load check valve or the flow control valve is leaking.

There is leakage between the piston and the cylinder. There is leakage between the tilt valve spool and the body. body.

Note: Remember that an O-ring seal failure in the circuit has the same effect as a major component failure.


Bulldozer Tilt Cylinder Drift Tests

Ripper Lift Cylinders Cylinders Drift Tests

Measure the tilt cylinder rod drift by using the following procedure:

Measure the ripper lift cylinder drift by using the following procedure:

1. Check the hydraulic oil temperature.

1. Check hydraulic oil temperature.

2. Fully retract the tilt cylinder.

2. Position the ripper so that the lowest point on the ripper is approximately 300 mm (12 inch) above ground. Position the tip cylinders at midstroke.


3. Lower the bulldozer in order to lift the front idlers off the ground. When the lift/tilt control valve is in HOLD, stop the engine. 4. Measure the extension of the rods from the cylinders. Record the distance that was measured. Compare the values with the chart. Note: The drift distance in the chart is for new machines. Table 7

Bulldozer Tilt Cylinder Drift Oil Temperature

28 to 48 C (83 to 118 F)

49 to 68 C (120 to 155 F)

69 to 88 C (156 to 190 F)

Measure the drift distance distance and the time. Compare 3. Measure the values with the chart.

Note: The drift distance in the chart is for new machines. Table 9

Ripper Lift Cylinder Drift Oil Temperature

28 to 48 C (83 to 118 F)

49 to 68 C (120 to 155 F)

69 to 88 C (156 to 190 F)

10 mm (.39 inch)

5 minutes

2.7 minutes

1.7 minutes






























Tests

Tests

1. Raise the rear of the machine off the ground by lowering the ripper. Put the ripper control lever in HOLD position. Shut off the engine and watch the ripper lift cylinder rods for movement.

1. Tip the ripper until the tip cylinders are fully retracted. Lower the ripper until the lift cylinders are fully extended. Put the ripper control lever in HOLD position. Shut off the engine and watch the ripper tip cylinder rods for movement.

2. Raise the ripper off the ground. Put the control lever in HOLD position. Shut off the engine and watch the ripper lift cylinder rods for movement. Table 10

Test Results



There is leakage between the piston and the cylinder. There is leakage between the ripper lift valve spool and the body.

Driftin Drifting g occurs occurs in test test 1.

Lift Lift circui circuitt makeup makeup valv valve e is leaking.


2. Tip the ripper forward until the tip cylinders are fully extended. Lower the ripper until the lift cylinders are fully extended. Put the ripper control lever in HOLD position. Shut off the engine and watch the ripper tip cylinder rods for movement. Table 12

Test Results



There is leakage between the piston and the cylinder. There is leakage between the ripper tip valve spool and the body.

Driftin Drifting g occurs occurs in Test 1.

The tip circui circuitt makeup makeup valve is leaking.

Note: If excessive cylinder drift is noted in both the ripper lift cylinder and the ripper tip cylinder, the problem may be in the ripper diverter valve.


Ripper Tip Cylinders Drift Tests

Note: If excessive cylinder drift is noted in both the ripper lift cylinder and the ripper tip cylinder, the problem may be in the ripper diverter valve.

Measure the ripper tip cylinder drift by using the following procedure:

Quick-Drop Valve Test

1. Check hydraulic oil temperature. 2. Fully retract the ripper tip cylinders and fully extend the ripper lift cylinders. 3. Measure the extension of the rods from the

Measure the actuation point of the quick-drop valve. Use the following procedure:

1. Measure the distance from the neutral point of the lower lever to the activation point for the




























To prevent personal injury when checks are made while the machine is in operation, make sure only approved personnel are on the machine. Keep other personnel personnel off the the machine machine and in view of of the operator. Make sure checks are done in an open area.

Steering Turn Diameter Check 1. Move the machine to a flat, dry open area. Ensure that there is a limited amount of track slip. Make sure that the steering linkage is adjusted. 2. Start and run the engine at HIGH IDLE. Raise all the implements to the FULL RAISE position and return the levers to the HOLD position. 3. Release the parking brake and put the transmission in FIRST SPEED FORWARD. 4. Place the steering control handle in the full steer left position. Keep all implement controls in the HOLD position. position. 5. Make a full 360 degree turn. 6. Stop the machine after the full turn. Lower all implements to the ground and stop the engine.

Illustration 38

g00491216

Full turn Diameter (A) Diameter of the turn

The machine will not turn. The turning radius is very gradual. Problem Checklist 1. The steering linkage is disconnected or broken. 2. The pump is not connected to the pump drive or the pump drive shaft is broken. 3. The oil level in the hydraulic tank is low. 4. The steering pump or the motor has failed.

7. Measure the distance (A), as shown. Distance (A) should be 1.4 to 2.0 m (4.6 to 6.6 ft).

5. There is no charge or pilot pressure.

8. Repeat steps 1 through 7 with the steering control handle in the FULL STEER RIGHT position.

6. The parking brake is ON. The problem is caused by the following causes:

9. The steering hydraulic system is operating correctly correctly if the distance is within the specificatio specification. n. If the distances are not within the specification, proceed to Step 10.

a. The linkage is misadjusted. b. The powertrain oil pressure is low.




























1. The charge pressure is low. The problem is caused by the following causes: a. The charge pump is worn.

c. There is excessive leakage on one side of the pilot valve. d. There is a blocked pump signal line from the pilot valve.

b. The cold oil bypass valve is worn. 3. Steering pump c. The charge pressure relief valve is set too low. a. The crossover relief/makeup valve is leaking. d. There is high leakage at the motor flushing valve. e. The steering pump or the steering motor has failed.

b. The pump controls are misadjusted or worn. c. The pump is worn or failed. 4. Steering motor

2. There is low pilot pressure. The problem is caused by the following causes: a. The tiller is improperly adjusted.

a. The motor is worn or failed. b. The flushing valve is worn.

b. Improperly set pilot valves.

Sprocket Speed Check

c. There is excessive leakage in the pilot valve.

Note: The check should be used primarily in a shop area after the machine has been repaired or rebuilt.

d. There is a blocked supply line to the pilot valve. 3. Steering pump a. The crossover relief/makeup valve is leaking. b. The pump controls are misadjusted or worn. c. The stops are incorrect or worn. 4. Steering motor a. The motor is worn or failed. b. The flushing valve is worn. Distance Distance (A) is too large in one direction direction in Steps

1. Move the machine to a flat open area. Lower the implements to the ground and stop the engine. 2. Separate the tracks and remove the final drive sprockets. Power Train Disassembly and Assembly, senr5387. 3. Before the checks are made, make sure that the steering linkage is correctly adjusted. Also, put a mark on both final drives. 4. Start the engine and run at HIGH IDLE. Release the parking parking brake and move the steering 5. Release control lever to the FULL STEER RIGHT position with the transmission in NEUTRAL.




























9. If the sprocket speeds are not within the tolerances, check the component operation. Also, check the adjustment of the tiller handle. If Step 6 is low, check the engine speed. If Step 7 is out of tolerance, excessive mechanical drag may be present in the differential steer unit and the final drives. 10. If a problem had been indicated by the checks, use Diagnostic Instrument Tests to get a more accurate indication of the location of the specific problem. 11. If the values that are found in Steps 6, 7, and 8 for both the FULL STEER RIGHT and the FULL STEER LEFT are within the specification, perform the following calculation in order to check the steering balance. Use the values that are found in Step 6. Add the value for FULL STEER LEFT to the value for FULL STEER RIGHT. The value should be 0 ± 1.1 rpm. 12. The value that is found in step 11 is out of the specification: The problem may be caused by a misadjusted pump control or a faulty pilot control valve.

Personal injury or death can result from sudden machine movement. Sudden movement of the machine can cause injury to persons on or near the machine. Prevent possible injury by performing the procedure that follows before working on the machine. Move Move the machine machine to a smooth smooth horizo horizonta ntall locati location. on. Move away away from from working working machines machines and personnel personnel and lower the buckets or implements (loader and backhoe) and stabilizers to the ground. Permit Permit only only one operator operator on the machine. machine. Keep all other personnel away from machine or in view of the operator. Engage the parking brake. Stop the engine. Move the hydraulic control levers to all positions to release the pressure in the hydraulic system. Table 13

13. When the checks, and the adjustments are complete, stop the engine. Remove all test equipment and connect the track.

Diagnostic Instrument Tests for the Implement Hydraulic System The test is used mainly to determine the location of a problem in the implement hydraulic circuit.

Required Tools 1U-5796 Pressure Differential Gauge 6V-3121 Multitach

1. Move the machine to a flat open area. Lower the implements to the ground and stop the engine.




























3. Connect the other ends of the hoses to the 1U-5796 Pressure Differential Gauge. Connect the hose for pressure tap (A) to the tee side of the P gauge. Connect Connect the hose from from pressure pressure tap (B) to the elbow side of the P gauge. gauge. 4. Install the 8T-0861 Gauge (60000 kPa (8700 psi)) on the tee side of the P gauge. gauge. 5. Make sure that the implement control linkage is correctly adjusted for the implement valves. 6. Install the 6V-3121 Multitach on the tachometer drive. 7. Start and run the engine at HIGH IDLE. Record the rpm. The reading should be 2080 ± 40 rpm. Refer to the Fuel Specifications (Zero T) for the most current specification for the engine. 8. With the engine at HIGH IDLE, move the bulldozer control lever halfway between HOLD and FULL RAISE. Record the readings on the P gauge while the bulldozer is still moving up. The reading on the P gauge gauge is margin margin pressur pressure e or the difference between pump discharge pressure pressure and signal signal pressure pressure from the implement implement control valve. The margin pressure should be 2100 ± 275 kPa (305 ± 40 psi). If the margin pressure is not correct then see the topic Compensator Valve Adjustments/Margin Pressure Adjustments for the correct procedure to make an adjustment. If the margin pressure is adjusted, the differential pressure should be held to 2100 ± 100 kPa (305 ± 15 psi).

9. With the engine at HIGH IDLE, move the bulldozer blade tilt lever to the maximum TILT LEFT or TILT RIGHT position. After the cylinder has hit the end of the stroke, the implement

11. Readings from Step 10 should be the following readings: a. 26200 ± 450 kPa (3800 ± 65 psi) b. 30 rpm or less below the reading that is recorded in Step 7 c. 350 kPa (50 psi) maximum with a maximum oil temperature of 66 C (150 F) (150 F) If all the readings are within the specification, the implement hydraulic pump should be good, but there could be a problem in the individual implement circuits.

12. Use the following checklists to help diagnose implement system problems that are based on the results of the above tests. Remove test equipment after all tests, adjustments, and needed repairs are completed. Reading A is too high or the reading is too low. Problem Checklist 1. The pressure cutoff needs to be adjusted. Note: If the pressure cutoff can not be adjusted, the pump or the compensator valve has failed. Reading A is within the specification. Reading A is too low. Reading B is correct and reading C is too high. The readings indicate a leak(s) in the signal network between the implement control valve and the implement pump compensator valve. The leak(s) could be caused by the following causes: Problem Checklist 1. There is dirt or foreign material in the orifice in






























Reading B is not correct and reading A is correct or too low. The readings indicate that excessive power is used by the pump in the implement pump stall condition. Problem Checklist 1. The setting on the main implement relief valve is too low or the valve is leaking. 2. The implement pump has failed. 3. The implement valve spool or the spool bore is badly scratched. scratched.

Implement Pump Discharge Pressure Tests The maximum and minimum implement pump discharge pressures are known values and the pressures can be tested. The tests are the following tests:Low Pressure Standby Test, High Pressure Stall Test, and Margin Pressure Test.

Illustration 40

g00527723

Implement Valve (A) Pump Discharge Pressure tap (B) Pressure tap (signal oil)

2. Install the tetragauge on pressure tap (A). 3. Start the engine and run at minimum rpm. Ensure that the parking brake is fully engaged. 4. Leave all controls in the HOLD position.

Personal injury or death can result from sudden machine movement.

5. The reading on the tetragauge should be approximately 3000 kPa (435 psi). The reading is the pump pressure output in the low pressure




























4. Start the engine and run at HIGH IDLE. 5. With the engine at HIGH IDLE, move the bulldozer blade tilt lever to the maximum TILT LEFT or TILT RIGHT position. After the cylinder is at the end of the stroke, the implement pump is at the stall condition. Note: Use Blocking plates on the lift circuit hoses for machines that are not equipped with tilt cylinders. Use Blocking plates on the lift circuit hoses for machines that do not have an installed bulldozer. 6. The pressure reading on the 8T-0861 Gauge should be 26200 ± 450 kPa (3800 ± 65 psi). The pressure reading on the P gauge gauge should should be less than 345 kPa (50 psi) at a maximum oil temperature of 66 C 66 C (150 F). Note: Do not hold the machine in the implement stall condition for more than 15 seconds at a time. 7. If the maximum pressure is too high or too low, the pressure cutoff needs to be adjusted.

Margin Pressure Test Put the engine at HIGH IDLE. Move the bulldozer control lever to a position that is halfway between the HOLD and the FULL RAISE. Record the

Personal injury or death can result from sudden machine movement. Sudden movement of the machine can cause injury to persons on or near the machine. Prevent possible injury by performing the procedure that follows before working on the machine. Move Move the machine machine to a smooth smooth horizo horizonta ntall locati location. on. Move away away from from working working machines machines and personnel personnel and lower the buckets or implements (loader and backhoe) and stabilizers to the ground. Permit Permit only only one operator operator on the machine. machine. Keep all other personnel away from machine or in view of the operator. Engage the parking brake. Stop the engine. Move the hydraulic control levers to all positions to release the pressure in the hydraulic system.




























4. When the pressure setting is adjusted, hold screw (4) with a hex wrench and tighten locknut (5) to a torque of 9 ± 1 N·m (7 ± 1 lb ft). 5. Do the High Pressure Stall Test again in order to make sure that the pressure setting is 23990 ± 515 kPa (3480 ± 75 psi).

Signal Network Bleed Procedure

Personal injury or death can result from sudden machine movement. Sudden movement of the machine can cause injury to persons on or near the machine. Prevent possible injury by performing the procedure that follows before working on the machine. Move Move the machine machine to a smooth smooth horizo horizonta ntall locati location. on. Move away away from from working working machines machines and personnel personnel and lower the buckets or implements (loader and backhoe) and stabilizers to the ground. Permit Permit only only one operator operator on the machine. machine. Keep all other personnel away from machine or in view of the operator.

Illustration 42 Implement Pump Pressure Compensator Valve (1) Screw (2) Locknut (3) Margin spool (4) Screw (5) Locknut (6) Pressure cutoff spool

g00491586

Engage the parking brake. Stop the engine. Move the hydraulic control levers to all positions to release the pressure in the hydraulic system.




























5. Repeat Step 4 for the LIFT valve and for the RIPPER valve. 6. Close off purge valve (1). Note: The procedure bleeds the signal network, only if the procedure is done in the above order. Any other order does not bleed all of the air from the signal network.

Resolver Network Check (Implement) A resolver is a check valve. The resolver compares two pressures. The lower pressure of the two pressures is blocked. The higher pressure or the higher signal goes to the next component in the resolver network. Each implement control valve has a resolver. The resolver compares the highest primary signal in the control valve to the highest primary signal in the next control valve. The signal resolver network is arranged in a series. The series stops at the pump compensator valve. The signal network can be easily checked. Start the engine and warm up the oil. Run the engine at HIGH IDLE for the check. Operate each control lever in the following order:

Illustration 44

g00491596

Resolver

The resolver in each section is located directly behind the actuator lever housing on the top of the valve body.

Quick-Drop Valve Adjustment




























Main Rel Relief ief Valve Adjust Adjustmen mentt (Impleme (Implement) nt) Table 16

Required Tools

Diagnostic Instrument Tests for the Steering Hydraulic System (7TL) The test is used mainly to determine the location of a problem in the steering hydraulic system.

1U-5216 Test Block Manifold

Personal injury or death can result from sudden machine movement. Sudden movement of the machine can cause injury to persons on or near the machine. Prevent possible injury by performing the procedure that follows before working on the machine.

Illustration 46

g00527726

Move Move the machine machine to a smooth smooth horizo horizonta ntall locati location. on. Move away away from from working working machines machines and personnel personnel and lower the buckets or implements (loader and backhoe) and stabilizers to the ground.

Implement Main Relief Valve (1) Retainer (2) Nut (3) Relief valve

The implement main relief valve has a setting that is higher than the pump cutoff pressure. Use the 1U-5216 Manifold to test the relief valve on the test

Permit Permit only only one operator operator on the machine. machine. Keep all other personnel away from machine or in view of the operator. Engage the parking brake. Stop the engine. Move the hydraulic control levers to all positions






























d. The pilot control valve is worn. 9. The reading on pressure gauges at pressure taps (C) and (D) should be 2500 ± 300 kPa (365 ± 45 psi). If the pressures on the gauges at pressure taps (C) and (D) are too high, then the charge pressure relief valve is improperly adjusted or worn or the oil temperature is too low. If the pressures are too low, then there is a problem in the charge circuit. The causes could be the following causes: a. The charge pressure relief valve is improperly adjusted or failed. Illustration 48 (1) Steering Motor (C) Pressure tap for the left steer pressure (D) Pressure tap for the right steer pressure

g00527729

b. There is a leak in the charge circuit. c. The motor or the motor flushing valve has




























Table 18

Steering Pump Cutoff Pressure Engine Speed

2240 r pm

Oil Temperature 65 ± 5 C (150 ± 10 F)

80 ± 5 C (175 ± 10 F)

40000 ± 1050 kPa (5800 ± 150 psi)

39500 395 00 ± 1050 kPa (5730 ± 150 psi)

Note: The above test conditions must be matched as closely as possible. Lower temperatures or speeds may result in higher pressures. 15. Determine if pressure (C) and pressure (D) are within the specification. Then determine if pressure (Y1) and pressure (Y2) are within the

Illustration 49 (E) Charge pump relief pressure tap

g00527730




























7. If the charge pressure is higher than the pressures that are specified, then the charge pressure relief valve could be worn or out of adjustment. 8. If the pressure on the gauge for tap (E) is lower than 1700 ± 300 kPa (245 ± 45 psi) during a neutral steer condition, check the following causes. a. There is a worn charge relief valve in the steering pump. b. There is a worn cold oil bypass valve in the pressure control valve. c. The motor flushing valve is worn or stuck open.

Charge Pressure Relief Valve Adjustment




























Neutral Adjustment for the Steering Pump Control Valve (Hydraulic Zero)

Personal injury or death can result from sudden machine movement. Sudden movement of the machine can cause injury to persons on or near the machine. Prevent possible injury by performing the procedure that follows before working on the machine. Move Move the machin machine e to a smooth smooth horizo horizonta ntall locati location. on. Move away away from from working working machines machines and personne personnell and lower the buckets or implements (loader and backhoe) and stabilizers to the ground.

Illustration 52 (1) Steering motor (C) Pressure tap for left steer pressure (D) Pressure tap for right steer pressure

g00527729




























8. If the readings are not within 100 kPa (15 psi), the control valve must be adjusted.

Checking Checking and Adjusting Adjusting Steering Pump Cutoff Pressure

Personal injury or death can result from sudden machine movement. Sudden movement of the machine can cause injury to persons on or near the machine. Prevent possible injury by performing the procedure that follows before working on the machine. Move Move the machine machine to a smooth smooth horizo horizonta ntall locati location. on. Move away away from from working working machines machines and personnel personnel and lower the buckets or implements (loader and backhoe) and stabilizers to the ground.






























Table 21

Steering Pump Cutoff Pressure Engine Speed

Oil Temperature 65 ± 5 C (150 ± 10 F)

80 ± 5 C (175 ± 10 F)




























Steering Pump Cutoff Pressure Adjustment

Steering Pump Case Pressure Test

Personal injury or death can result from sudden machine movement.




























5. Start and run the engine at HIGH IDLE. 6. The gauge reading must be less than 175 kPa (25 psi). 7. If the gauge reading is more than 175 kPa (25 psi), check the hose from the pressure

5. Place the throttle in the shut off position. Without starting the engine, crank the engine for 15 seconds at a time until the pressure starts to show on the pressure gauge. Crank the engine at one minute intervals in order to allow the starter to cool.




























Steering Pilot Valve




























Note: The pilot valve may move if the transmission control cables are too tight or misadjusted. 9. Verify that the tiller moves smoothly in both directions. 10. Connect the hydraulic lines. Start the engine,





















































































































































































































































Manual de Sistema Hidraulico D9R 2.pdf

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