LIFT LIFT CYLI CYLIND NDE ERS ALL MODELS, EXCEPT EXCEPT H8.00-12.00XM H8.00-12.00XM (H170-280HD) [F007, G007]; H13.00-16.00XM H13.00-16.00XM (H300-360HD) [E019, F019]; H10.00-12.00XM-EC H10.00-12.00XM-EC (H360HD-EC) [E019, F019]; H20.00-32.00F H20.00-32.00F (H440-700FS) [E008]; H36.00-48.00E H36.00-48.00E (H800-1050E) [D117]; H3.50-5.50XM H3.50-5.50XM (H70-120XM) [K005, L005]; S3.50-5.50XM, S3.50-5.50XM, S5.50XMS (S70-120XM, S120XMS) [E004, [E004, F004]
PART NO. 910119
4000 SRM 135
SAFETY PRECAUTIONS MAINTENANCE AND REPAIR When lifting parts or assemblies, make sure all slings, chains, or cables are correctly fastened, fastened, and that the load being lifted lifted is balanced. balanced. Make sure the crane, cables, and chains have the capacity to support the weight of the load. • Do not lift heavy parts by hand, use a lifting mechanism. • Wear safety glasses. • DISCONNECT THE BATTERY CONNECTOR before doing any maintenance or repair on electric lift trucks. • Disconnect the battery ground cable on internal internal combustion lift trucks. trucks. • Always use correct blocks blocks to prevent the unit from rolling or falling. See HOW TO PUT THE LIFT TRUCK ON BLOCKS in the Operating Manual or Manual or the Periodic the Periodic Maintenance section. nance section. • Keep the unit clean and the working area clean and orderly. • Use the correct tools for the job. • Keep the tools clean and in good condition. • Always use HYSTER APPROVED parts parts when making repairs. repairs. Replacement Replacement parts parts must meet or exceed the specifications of the original equipment manufacturer. • Make sure all nuts, bolts, snap rings, and other fastening devices are removed before using force to remove parts. • Alway Alwayss fast fasten en a DO NOT NOT OPERA OPERATE TE tag tag to the the cont contro rols ls of the the unit unit when when makin making g repai repairs rs,, or if the unit needs repairs. • Be sure to follow the WARNING and WARNING and CAUTION notes CAUTION notes in the instructions. • Gasoline Gasoline,, Liqui Liquid d Petrol Petroleum eum Gas (LPG), (LPG), Compres Compressed sed Natura Naturall Gas (CNG), (CNG), and Diesel Diesel fuel fuel are flammable. Be sure to follow the necessary necessary safety precautions precautions when handling handling these fuels and when working on these fuel systems. • Batteries Batteries generate generate flammable gas when they are being charged. charged. Keep fire and sparks away from the area. Make sure the area is well ventilated.
NOTE: The following symbols and words indicate safety information in this manual:
WARNING Indicates a condition that can cause immediate death or injury!
CAUTION Indicates a condition that can cause property damage!
Lift Cylinders
Table of Contents
TABLE OF CONTENTS Safety Procedures Procedures When Working Working Near Mast............................ Mast........................................ ....................... ....................... ........................ ........................ ....................... ........... General General ............ ........................ ........................ ........................ ........................ ........................ ........................ ....................... ....................... ........................ ....................... ....................... ........................ ................. ..... Description Description ........... ....................... ....................... ....................... ........................ ........................ ....................... ....................... ........................ ...................... ...................... ........................ ........................ .............. .. Lowering Lowering Control Control Valve............................... alve........................................... ........................ ........................ ........................ ........................ ........................ ....................... ...................... ............... .... Cylinders Cylinders (General) (General) ............ ........................ ....................... ....................... ........................ ........................ ........................ ........................ ........................ ....................... ....................... ................. ..... Cylinders Cylinders (H520-620B, (H520-620B, H700-800A) H700-800A) .......... ..................... ....................... ........................ ........................ ....................... ....................... ........................ ........................ ................. ..... Retainer Retainer,, Install.............. Install.......................... ....................... ....................... ........................ ........................ ........................ ....................... ....................... ........................ ........................ ................. ..... Cylinders Cylinders (H360-460 (H360-460B) B) ............ ....................... ....................... ........................ ........................ ........................ ........................ ........................ ....................... ..................... ...................... .............. .. Cylinders Cylinders (Two-Speed (Two-Speed).................... )............................... ....................... ........................ ........................ ........................ ........................ ........................ ....................... ....................... ................. ..... Lift Cylinder Cylinder Repair................... Repair............................. ...................... ........................ ........................ ....................... ....................... ........................ ........................ ........................ ....................... ............... .... Lift Cylinder Cylinder Removal Removal Without Without Removing Removing Mast................... Mast............................... ......................... ......................... ........................ ........................ ...................... .......... Standard Standard Masts With With Main Lift Lift Cylinder Cylinder Fastened Fastened to Crossmem Crossmember ber of Inner Inner Mast............ Mast......................... ................ ... Standard Standard and Full Full Free-Lift Free-Lift Masts With Lift Cylinder Cylinder Fastened Fastened to to Crosshead Crosshead .................. .............................. ................. ..... Masts That That Have Two Cylinders, Cylinders, Main Main Lift Cylinder Cylinder and Free-Lift Free-Lift Cylinder Cylinder ............ ........................ .......................... .............. Disassemble Disassemble ................. ............................. ........................ ....................... ....................... ........................ ........................ ....................... ....................... ...................... ...................... ........................ .............. .. Assemble ................. ..... ......................... ......................... ......................... ............. ............. ......................... ........................ ......................... ......................... ......................... ......................... ...................... .......... Lift Cylinder Cylinder Installatio Installation n in Mast ................... .............................. ....................... ........................ ........................ ....................... ....................... ........................ ....................... ........... Standard Standard Masts With With Main Lift Lift Cylinder Cylinder Fastened Fastened to Crossmem Crossmember ber of Inner Inner Mast............. Mast......................... ............... ... Standard Standard and Full Full Free-Lift Free-Lift Masts With Lift Cylinder Cylinder Fastened Fastened to to Crosshead Crosshead .................. .............................. ................. ..... Chevron-Style Chevron-Style Packing Packing ............ ........................ ........................ ........................ ......................... ......................... ........................ ........................ ...................... ...................... ....................... ........... Chevron-Style Chevron-Style Packing Packing Installat Installation ion on Piston........ Piston.................... ........................ ........................ ........................ ........................ ........................ ..................... ......... Chevron-Style Chevron-Style Packing Packing Installat Installation ion in Packing Packing Gland Gland ........... ....................... ........................ ........................ ........................ ........................ ................ .... Lift Cylinders for VISTA ® Masts................. Masts........................... ...................... ........................ ........................ ....................... ....................... ........................ ........................ ..................... ......... Description.................... Description................................ ........................ ....................... ....................... ........................ ........................ ....................... ....................... ........................ ........................ ....................... ........... Lowering Lowering Control Valve....... Valve................... ........................ ........................ ........................ ........................ ........................ ........................ ........................ ....................... ...................... ........... Remove ........... ....................... ........................ ...................... ...................... ........................ ........................ ........................ ........................ ........................ ....................... ....................... ....................... ............... .... Disassemble Disassemble ................. ............................. ........................ ....................... ....................... ........................ ........................ ....................... ....................... ...................... ...................... ........................ .............. .. Assemble ................. ..... ......................... ......................... ......................... ............. ............. ......................... ........................ ......................... ......................... ......................... ......................... ...................... .......... Install Install ........... ...................... ....................... ........................ ........................ ....................... ....................... ........................ ........................ ....................... ....................... ........................ ........................ ................. ..... Main Lift Lift Cylinders................. Cylinders........................... ...................... ........................ ........................ ........................ ........................ ........................ ....................... ....................... ..................... ......... Free-Lift Free-Lift Cylinder Cylinder ...................... .................................. ....................... ....................... ........................ ........................ ....................... ....................... ........................ ........................ ................. ..... Lift System System Leak Check Check ..................... ................................. ........................ ........................ ....................... ....................... ........................ ........................ ....................... ....................... ................. ..... Specifications. Specifications............ ....................... ........................ ...................... ...................... ........................ ........................ ....................... ....................... ........................ ........................ ........................ ..................... ......... Troublesh Troubleshootin ooting................. g............................. ........................ ........................ ........................ ........................ ....................... ....................... ........................ ....................... ....................... ....................... ...........
1 5 5 5 8 8 8 10 12 14 14 14 14 14 16 16 18 18 18 18 19 21 22 22 22 24 25 26 27 27 27 28 29 30
This section is for the following models: All Models, ExceptH8.00-12.00XM (H170-280HD) [F007, G007]; H13.00-16.00X H13.00 -16.00XM M (H300-360HD) (H300-360HD) [E019, F019]; H10.00-12.00X H10.00-12.00XM-EC M-EC (H360HD-EC) (H360HD-EC) [E019, F019]; H20.00-32.00F H20.00-32.00F (H440-700FS) (H440-700FS) [E008]; H36.00-48.00E (H800-1050E) [D117]; H3.50-5.50XM (H70-120XM) [K005, L005]; S3.50-5.50XM, S3.50-5.50XM, S5.50XMS (S70-120XM, (S70-120XM, S120XMS) S120XMS) [E004, F004]
©2003 HYSTER COMPANY COMPANY
i
"THE QUALITY KEEPERS"
HYSTER APPROVED PARTS
4000 SRM 135
Safety Procedures When Working Near Mast
Safety Procedures When Working Near Mast The following procedures must be used when inspecting or working near the mast. Additional precautions and procedures can be required when repairing or removing the mast. See the correct Service Manual section for the specific mast being repaired.
WARNING Mast parts are heavy and can move. Distances between parts are small. Serious injury or death can result if part of the body is hit by parts of the mast or the carriage. • Never put any part of the body into or under the mast or carriage unless all parts are completely lowered or a safety chain is installed. Also make sure that the power is OFF and the key is removed. Put a DO NOT OPERATE tag in the operator’s compartment. • Be careful of the forks. When the mast is raised, the forks can be at a height to cause an injury. • Do NOT climb on the mast or lift truck at any time. Use a ladder or personnel lift to work on the mast. • Do NOT use blocks to support the mast weldments nor to restrain their movement. • Mast repairs require disassembly and removal of parts and can require removal of the mast or carriage. Follow the repair procedures in the correct Service Manual for the mast.
OR 2. If parts of the mast must be in raised position, install a safety chain to restrain the moving parts of the mast. Connect moving parts to a part that does not move. Follow these procedures: a. Put the mast in a vertical position. b. Raise the mast to align the bottom crossmember of the inner weldment with a crossmember on the outer weldment. See Figure 1, Figure 2, and Figure 3. c.
Use a 12 mm (0.5 in.) minimum safety chain with a hook to fasten the crossmembers together so that the movable member cannot lower. Put the hook on the back side of the mast. Make sure the hook is completely engaged with a link in the chain. Make sure the safety chain does not touch lift chains or chain sheaves, tubes, hoses, fittings or other parts on the mast.
d. Lower the mast until there is tension in the safety chain. If running, stop the engine. Apply the parking brake. Install a DO NOT REMOVE tag on the safety chain(s). e.
Install another safety chain 12 mm (0.5 in.) minimum between the top or bottom crossmember of the carriage and a crossmember on the outer weldment.
WHEN WORKING NEAR THE MAST ALWAYS: 1.
Lower the mast and carriage completely. Push the lift/lower control lever forward and make sure there is no movement in the mast. Make sure that all parts of the mast that move are fully lowered.
3. Apply the parking brake. After lowering or restraining the mast, shut off the power and remove the key. Put a DO NOT OPERATE tag in the operator’s compartment.
1
Safety Procedures When Working Near Mast
1. INNER WELDMENT 2. OUTER WELDMENT
4000 SRM 135
3. HOOK 4. CARRIAGE Figure 1. Mast
2
4000 SRM 135
1. INNER WELDMENT 2. TILT CYLINDERS
Safety Procedures When Working Near Mast
3.
HOOK
Figure 2. Mast
3
Safety Procedures When Working Near Mast
Figure 3. Two-Stage, Free-Lift, Three-Stage, and Four-Stage Masts
4
4000 SRM 135
4000 SRM 135
Description Legend for Figure 3
A. TWO-STAGE MAST B. FREE-LIFT MAST
C. THREE-STAGE MAST D. FOUR-STAGE MAST
1. 2. 3. 4.
5. 6. 7. 8.
OUTER WELDMENT INNER WELDMENT INTERMEDIATE WELDMENT FIRST INTERMEDIATE WELDMENT
HOOK FREE-LIFT CYLINDER CROSSMEMBER CROSSMEMBER
General This section has the description for lift cylinders used in masts and the instructions for their repair. There are many different sizes of lift cylinders used in Hyster Company lift trucks. The operation and repair procedures for the different lift cylinders are similar. The illustrations in this section are for typical
lift cylinders. All of the variations in lift cylinders used in lift trucks are not shown. A section for Lift Cylinders for VISTA ® Masts is included later in this section.
Description All lift cylinders are single-acting cylinders. See Figure 4. The hydraulic force is applied only in one direction. When hydraulic oil enters one end of the lift cylinder, the hydraulic force extends the piston rod. When the force is removed, the weight of the carriage and inner mast retracts the piston rod. A common maintenance problem is the repair of oil leaks from the seals and wiper around the piston rod. If the bore of the shell of the lift cylinder is damaged and cannot be repaired, the lift cylinder must be replaced.
LOWERING CONTROL VALVE A lowering control valve is installed in the inlet port. See Figure 5. It permits easy entry of hydraulic oil into the cylinder, but gives a restriction when the rod is retracted. This restriction gives limits to the speed that a load on the forks can be lowered. There are two types of lowering control valves. Both types have the same function and similar operation. The most common type of valve has a design that has good operation using large flows and lower pressures. Some lift trucks have a lift system design using higher pressures and a lower flow. These systems need a different type of lowering control valve.
The most common type of lowering control valve uses these parts: (1) a special fitting for the valve body, (2) a spring, and (3) a special washer. There is a variation in the shapes of the special washer. Different lift cylinders use different shapes of special washers. The volume of the hydraulic oil flowing through the inlet port controls the shape of the special washer. (A typical shape of a special washer is shown in Figure 5.) When the piston rod is lowered, the oil flow pushes against the special washer and spring. When the oil flow reaches the limit, the special washer is moved against the special fitting. The oil then flows only through the hole in the center of the special washer. This restriction permits the piston rod to lower only at a maximum controlled speed. The other type of lowering control valve uses these basic parts: (1) valve body, (2) spring, (3) washer, (4) cylinder, (5) orifice sleeve, (6) plunger, and (7) main sleeve. The orifice sleeve position is controlled completely by oil flow. The plunger position is controlled by oil pressure and spring tension. During lifting, oil entering the lift cylinder goes through the center of the main sleeve to the large holes. The oil flow through the plunger and bore moves the orifice sleeve to the end of the plunger. The flange of the orifice sleeve is then aligned with the large part of the bore in the body. This alignment lets the oil flow past the orifice sleeve to the cylinder.
5
Description
4000 SRM 135
A. INSTALLED
B. NOT INSTALLED
1. 2. 3. 4. 5. 6.
7. RETAINER 8. WIPER SEAL 9. BACKUP RING 10. O-RING 11. ROD 12. SINGLE-LIP SEAL
LOWERING CONTROL VALVE PISTON BEARING CHECK VALVE SHELL NYLON RING
Figure 4. Two-Speed Lift Cylinder During lowering, oil from the lift cylinder moves the orifice sleeve. The orifice sleeve moves away from the larger inner diameter area of the bore in the valve body. This movement makes a restriction to the oil flow. As the pressure increases, the plunger begins to move against the spring. The movement begins to close the openings of the large holes in the main
6
sleeve. Additional pressure will push the plunger against the main sleeve to close the large holes completely. All the oil must then go through the small holes to the center of the main sleeve. This restriction permits the piston rod to lower only at a maximum controlled speed.
4000 SRM 135
Description
A. LOW PRESSURE DESIGN B. LOWERING C. RESTRICTED FLOW
D. HIGH PRESSURE DESIGN E. LIFTING F. FREE FLOW
1. 2. 3. 4.
5. ORIFICE SLEEVE 6. PLUNGER 7. MAIN SLEEVE
SPECIAL FITTING OR VALVE BODY SPRING SPECIAL WASHER CYLINDER
Figure 5. Lowering Control Valves
7
Description
CYLINDERS (GENERAL) Standard masts use a single-stage lift cylinder. Most three-stage and four-stage masts use two single-stage lift cylinders. A single-stage lift cylinder has one piston rod. See Figure 6. Most full free-lift masts and some three-stage masts use a two-stage lift cylinder. A two-stage lift cylinder has two telescopic piston rods. See Figure 7. The two-stage lift cylinder operates similar to a one-stage lift cylinder. Hydraulic pressure pushes the primary (larger) piston rod from the cylinder first because it has a larger diameter. The secondary piston rod moves with the primary piston rod. When the primary piston rod reaches the limit of its stroke, the secondary piston rod extends from the primary piston rod. Spacers are used in some cylinders to give a limit to the stroke of the piston rod. Worn spacers must be replaced with the same size spacer. Most of the lift cylinders use a single-lip seal assembly to prevent hydraulic oil leaks past the piston and past the retainer. See Figure 4. There are many lift cylinders in use that have an older design chevron-style packing. The chevron-style packing can be replaced with a seal kit that has the newer single lip seal and an adaptor. There are no replacements of single lip seals for chevron-style packing for lift trucks over 7,000 kg (15,000 lb) capacity. Lift cylinders and other hydraulic parts can have internal leaks. Internal leakage will increase as the temperature of the hydraulic oil increases. The internal leak rate of the hydraulic system is normally checked after every 1000 hours of operation. See Lift System Leak Check for test procedures and leakage rates within the specifications. During operation, some leakage of hydraulic oil can move past the piston seal to the rod side of the piston. A small leakage is permitted if the internal leak rate of the hydraulic system is not greater than the specification. An internal check valve is installed in
8
4000 SRM 135
the piston of many of the lift cylinders. When the rod extends, the pressure increases more quickly on any oil in the rod end of the cylinder. The hydraulic oil transfers through the check valve to the piston end of the cylinder. This action prevents hydraulic damage to the wiper seal. See Figure 8. Lift cylinders that do not have an internal check valve have a drain line on the outside of the cylinder shell.
CYLINDERS (H520-620B, H700-800A) The rod side of the lift cylinder is used for the storage of hydraulic oil on the H520-620B and H700-800A lift trucks. This storage decreases the required size of the hydraulic tank. When the piston raises in the cylinder, the oil on the rod side of the piston transfers to the hydraulic tank. When the piston lowers in the cylinder, some of the oil transfers to the rod side of the cylinder. Approximately one half of the oil in the bottom of the cylinder goes through the main control valve to the rod side of the cylinder. See the Main Control Valve of Service Manual for more information. See Figure 9.
Retainer, Install 1. Install the retainer over the piston and into the cylinder. Make sure the single-lip seal assembly, the O-ring, and thebackup ring are not damaged. See Figure 9. 2. Turn the retainer ring into the threads in the cylinder. Turn the retainer ring until it is even with the top of the cylinder. 3. Install the capscrews loosely. 4. The stroke of the cylinder rod can be adjusted by turning the retainer ring one-half turn in either direction. 5. Install and tighten the setscrew. 6. Tighten the capscrews to 36 to 46 N•m (27 to 34 lbf ft).
4000 SRM 135
Description
A. MAIN LIFT CYLINDER
B. FREE-LIFT CYLINDER
1. 2. 3. 4. 5. 6. 7. 8.
9. ROD ASSEMBLY 10. SPACER 11. TO SENSING PORT FOR PHASING VALVE PRESSURE 12. LOWERING CONTROL VALVE (ALL CYLINDERS) 13. PISTON RING 14. CUSHION RING
WIPER RING SINGLE-LIP SEAL BEARING O-RING RETAINER CHAIN ANCHOR MOUNT HYDRAULIC LINE MOUNT INTERNAL CHECK VALVE
Figure 6. Single-Stage Lift Cylinders
9
Description
4000 SRM 135
CYLINDERS (H360-460B) The lift cylinders used in the H360-460B lift trucks are displacement cylinders. The design and repairs for these cylinders are similar to the other lift cylinder in this section. A displacement cylinder does not have a piston or piston seal. The rod diameter is almost the same as the inside diameter of the cylinder. There are wear rings on the rod that are the bearings between the rod and the walls of the cylinder. The wiper seal at the top of the cylinder is also the high-pressure seal for these cylinders. The wiper seal has chevron-style packing. See Figure 10.
1. 2. 3. 4.
WIPER RING RETAINER SEAL SCREW (DO NOT CHANGE LENGTH) 5. PRIMARY ROD ASSEMBLY 6. SPACERS 7. BEARING
8. PISTON HALF (1 OF 2) 9. INTERNAL CHECK VALVE 10. SINGLE-LIP SEAL 11. SECONDARY ROD ASSEMBLY 12. O-RING 13. PLUG
Figure 7. Two-Stage Lift Cylinder
A. INSTALLED
B. NOT INSTALLED
1. 2. 3. 4.
5. SINGLE-LIP SEAL 6. O-RING 7. NYLON BACKUP RING
POPPET SPRING SEAL INLET AND OUTLET PORT
Figure 8. Internal Check Valve and Single-Lip Seal
10
4000 SRM 135
Description
A. LOWERING CONTROL VALVE 1. 2. 3. 4.
SETSCREW (1) CAPSCREW (2) RETAINER RING SINGLE-LIP SEAL ASSEMBLY
5. 6. 7. 8. 9.
RETAINER BACKUP RING O-RING CYLINDER SHELL ROD
10. SPACER 11. PISTON 12. PISTON RING NUT 13. NYLON SETSCREW 14. SPRING
15. FLANGE 16. SPACER PLATE 17. SPACER 18. VALVE BODY 19. SPECIAL WASHER
Figure 9. Lift Cylinder for H700-800A
11
Description
4000 SRM 135 Legend for Figure 10 NOTE: OIL LEAKAGE IS NOT CONTROLLED BY THE TORQUE ON THE PACKING GLAND. TIGHTEN THE PACKING RETAINER TO STOP OIL LEAKS. REPLACE CHEVRON-STYLE PACKING WHEN PACKING RETAINER CANNOT COMPRESS PACKING FURTHER TO CONTROL OIL LEAKS. DO NOT TIGHTEN MORE THAN NECESSARY TO STOP OIL LEAKS. 1. WIPER 2. NYLON RING 3. CHEVRON-STYLE PACKING 4. BACKUP RING 5. O-RING 6. ROD HEAD
7. PACKING RETAINER 8. PACKING GLAND 9. CYLINDER SHELL 10. INLET AND OUTLET PORT 11. WEAR RING
CYLINDERS (TWO-SPEED) Two-speed lift cylinders are single-stage lift cylinders with a special valve and path for the hydraulic oil. The lift cylinder is filled with oil on both sides of the piston. For loads less than 45% of the rated capacity, the cylinder rod can be extended at high speed. When the cylinder rod extends, the oil on the rod side of the piston transfers to the bottom of the piston. When the oil transfers, the increase almost doubles the flow of oil to the base of the cylinder. The pump pressure is applied to both sides of the piston. The area on the bottom of the piston is greater than the rod side of the piston. The difference in force pushes the piston up the cylinder. See Figure 11. For loads greater than 45% of capacity, the cylinder rod extends at normal speed. A special valve senses the increased oil pressure caused by the load. The oil is returned from the rod side of the lift cylinder to the hydraulic tank. All of the pump pressure is applied to the bottom side of the piston. The cylinder rod extends at a slower speed, but can lift a greater load. The two-speed lifting system is used only with standard masts. A two-speed lift system is used on the following lift trucks:
Figure 10. Displacement Cylinders
12
S60-80B
H150-250E
S125-150A
H150-275H
H60-80C
H250-300A
H300-350B
P125-180A
H110-150F
P150-200B
4000 SRM 135
Description
A. HIGH-SPEED OPERATION FOR NO LOAD OR LIGHT LOADS B. NORMAL OPERATION FOR RATED CAPACITY LOAD OR HEAVY LOADS 1. FORCE 2. FROM HYDRAULIC PUMP
3. GREATER LIFTING FORCE 4. TO HYDRAULIC TANK Figure 11. Two-Speed Lift Cylinders
NOTE: The maximum loads that the above models will lift at high speed are shown on Table 1. Table 1. Lift Trucks with Two-Speed Lift Cylinders Model
Load
S60-100B
1589 to 2043 kg (3500-4500 lb)
H60-80C
1589 to 2043 kg (3500 to 4500 lb)
H110-150F
1589 to 2043 kg (3500 to 4500 lb)
S125-150A
2270 to 2724 kg (5000 to 6000 lb)
H150-200ES, Standard Masts
2270 to 3087 kg (5000 to 6800 lb)
P125-180A, Standard Masts
2270 to 3087 kg (5000 to 6800 lb)
H150-250E, Heavy Duty Masts
3133 to 4041 kg (6900 to 8900 lb)
P125-180A, Heavy Duty Masts
3133 to 4041 kg (6900 to 8900 lb)
H250-300A
4540 to 4994 kg (10,000 to 11,000 lb)
This table shows the approximate maximum load that the mast will lift at high speed. Loads greater than those shown will cause the mast to lift at normal speed. These loads will have a variation because of the different attachments that can be installed on the lift truck.
13
Lift Cylinder Repair
4000 SRM 135
Lift Cylinder Repair LIFT CYLINDER REMOVAL WITHOUT REMOVING MAST
7. Remove the capscrew and the plate from the lower side of the cylinder.
Remove the carriage before the lift cylinder. See the procedure described in the Masts section. If the mast must be removed for repairs, then remove the lift cylinder when the mast is disassembled. Remove the lift cylinder from the mast as described in the following paragraphs.
8. Raise the cylinder and move it away from the mast. Move the lift cylinder to a position where it can be disassembled.
Standard Masts With Main Lift Cylinder Fastened to Crossmember of Inner Mast
1. Remove the lift chains and chain anchors from the mast and the lift cylinder. Connect a sling to the upper area of the lift cylinder. Raise the lifting mechanism until the sling is tight. See Figure 12 and Figure 13.
1.
2.
Fully lower the mast. Loosen, but do not disconnect the capscrew that fastens the cylinder rod to the crossmember of the inner mast. Clean the area next to the fittings that connect the hydraulic lines to the lift cylinder. Put a drain pan under the area where the hydraulic lines will be disconnected. Disconnect the hydraulic lines and put a cap on each open fitting.
WARNING Make sure the lifting mechanism has enough capacity to lift the loads. See the Weight Guide for lift cylinders in Table 2. 3.
4.
5.
Connect a lifting mechanism to the inner mast. Lift the inner mast approximately 300 mm (12 in.). Fasten the inner and outer masts together at the crossmembers with a heavy chain. Make sure that the inner mast cannot move. Remove the lifting mechanism. Connect a heavy-duty sling to the upper part of the cylinder. Raise the lifting mechanism until the sling is tight. Make sure the sling will not slide. Remove the capscrew and washer connecting the piston rod to the inner mast. Remove the spacer.
CAUTION Oil can come out of the cylinder fittings with pressure when retracting the rod. 6.
14
Loosen the cap on the lower fitting of the cylinder. Manually retract the piston rod.
Standard and Full Free-Lift Masts With Lift Cylinder Fastened to Crosshead
2. Remove the capscrews that connect the piston rod to the crosshead. 3. Disconnect and remove the crosshead assembly from the mast. Make a note of the shim arrangement on the crosshead guide. 4. Clean the area next to the fittings that connect the hydraulic lines to the lift cylinder. Put a drain pan under the area where the hydraulic lines will be disconnected. Disconnect the hydraulic lines and put a cap on each open fitting. 5. Remove the snap ring that connects the bottom of the lift cylinder to the outer mast. 6. Raise the lift cylinder and move it away from the mast. Move the lift cylinder to a position where it can be disassembled.
Masts That Have Two Cylinders, Main Lift Cylinder and Free-Lift Cylinder 1. Remove the free-lift cylinder as described in the section above for removing a lift cylinder fastened to a crosshead. 2. Remove the main lift cylinder as described in the section above for removing a lift cylinder fastened to an inner mast.
4000 SRM 135
Lift Cylinder Repair
1. 2. 3. 4. 1. CHAIN GUARD 2. CROSSHEAD ASSEMBLY 3. SNAP RING 4. SHEAVE 5. BEARING
6. CHAIN ANCHOR 7. SPECIAL WASHER 8. LOCK NUT 9. SPACER 10. WEAR PLATE 11. PAD
SHEAVE SNAP RING CROSSHEAD CYLINDER GUIDE ASSEMBLY
5. 6. 7. 8. 9.
CHAIN ANCHOR WASHER AND NUT SHIM GUIDE SHOE BEARING
Figure 13. Free-Lift Cylinder and Crosshead
Figure 12. Standard Mast Cylinder and Crosshead
15
Lift Cylinder Repair
DISASSEMBLE WARNING Use slings and a crane to handle and disassemble the lift cylinders of most lift trucks. Make sure that the crane and slings can lift the load. See Table 2.
CAUTION
4000 SRM 135
The spacers control the maximum stroke of the piston rod assembly. If a new spacer is necessary, make sure the same size spacer is installed. 1. Install the internal check valve. Make sure the arrow on the internal check valve is toward the base of the piston.
CAUTION
Carefully disassemble and assemble the lift cylinders so that the rods and sliding surfaces are not damag ed.
A difficult and important step in assembling cylinders is the correct installation of the seals without damage. Most cylinder maintenance is caused by seal leakage.
NOTE: Disassembly of single-stage and two-stage lift cylinders is the same except the two-stage lift cylinder has a second piston rod assembly. The disassembly of the secondary piston rod assembly is similar to the disassembly of the primary piston rod assembly.
2. Install the seal and bearing (and spacer if equipped) on the rod piston. Use shim material and a band clamp as a guide to move the single-lip seal past the threads of the shell.
1.
Loosen the retainer with a spanner. Disconnect the retainer from the shell. See Figure 14 and Figure 15.
2.
Remove the cap from the inlet and slide the piston rod assembly from the shell. Use drain pans for the hydraulic oil.
3.
Remove the retainer from the piston rod. Remove and discard the O-rings, seals, and bearings.
4.
Remove the internal check valve.
5.
Remove the lowering control valve.
6.
Clean all the parts. Check the sliding surfaces for damage. Repair or replace any damaged parts.
ASSEMBLE NOTE: Lubricate all internal parts of the lift cylinder with hydraulic oil during assembly. Use new O-rings, seals and bearings. Apply lubricant during assembly. Packing lubricant (Part Number 186061) is available. Make sure the single-lip seal assemblies are installed with the O-ring toward the base of the lift cylinder. See Figure 8.
16
3. Carefully push piston and piston rod into the shell. Release the band clamp on the seal when the seal travels past the threads of the shell. 4. Install the seals, O-rings, and bearings (when used) in the retainer. If the wiper seal has a spring backup ring, the spring must be toward the base of the lift cylinder. 5. Carefully install the retainer on the piston rod. 6. Engage the threads and tighten the retainer in the shell to the correct torque. Use a correct spanner. Do not hit the retainer with a hammer and driver.
CAUTION When the screw is installed on two-stage cylinders, never use a screw longer than 9.5 mm (0.375 in.). A longer screw will touch and damage the primary piston rod. Always install a seal under the head of the screw. If you do not install the screw and seal, the cylinder will have leaks. 7. Install the lowering control valve. Make sure the special washer and the spring are installed correctly. A wrong installation can cause the load to lower too fast.
4000 SRM 135
1. 2. 3. 4. 5. 6.
Lift Cylinder Repair
PLUG O-RING RETAINER WIPER RING SINGLE-LIP SEAL BEARING
7. O-RING 8. CYLINDER SHELL 9. CYLINDER ROD 10. SPACER 11. INTERNAL CHECK VALVE 12. O-RING
13. WASHER 14. SNAP RING 15. BACKUP RING 16. SINGLE-LIP SEAL 17. BEARING
Figure 14. Single-Stage Lift Cylinder
1. 2. 3. 4. 5. 6. 7. 8.
PLUG RETAINER BEARING O-RING SINGLE-LIP SEAL WIPER RING RETAINER SECONDARY CYLINDER ROD
9. SPACER 10. BEARING 11. SINGLE-LIP SEAL 12. BACKUP RING 13. PRIMARY CYLINDER ROD 14. SPACER 15. O-RING 16. PISTON RING HALF (2)
17. SNAP RING 18. WASHER 19. INTERNAL CHECK VALVE 20. CYLINDER 21. SCREW 22. SEAL
Figure 15. Two-Stage Lift Cylinder
17
Lift Cylinder Repair
LIFT CYLINDER INSTALLATION IN MAST Standard Masts With Main Lift Cylinder Fastened to Crossmember of Inner Mast 1.
2.
3.
Put the lift cylinder into position in the mast. Make sure the base of the lift cylinder is aligned correctly on its mount. Connect a chain to the upper section of the lift cylinder and the overhead guard. Make sure the chain will hold the lift cylinder in position until it can be fastened to the mast. Connect a lifting mechanism to the inner mast.
CAUTION Do not connect a wrench to the sliding surface of the piston rod. Any damage to the sliding surface will cause leaks. 4.
Disconnect the inner mast from the outer mast. Lower the inner mast until it touches the piston rod. Align the holes of the inner mast and the piston rod.
5.
Install capscrews, washer, and spacer to fasten the lift cylinder to the crossmember of the inner mast.
6.
Fasten the base of the lift cylinder to the crossmember of the outer mast with a capscrew and plate.
7.
Connect the hydraulic lines.
8.
Install the carriage.
Standard and Full Free-Lift Masts With Lift Cylinder Fastened to Crosshead 1.
18
Put the lift cylinder into position in the mast. Align the guide pin with the hole in the bottom crossmember.
4000 SRM 135 2. Install the crosshead assembly in the mast. Align the holes in the piston rod and the crosshead. 3. Fasten the crosshead to the piston rod with capscrews. 4. Fasten the base of the lift cylinder to its mount with a snap ring. 5. Connect the hydraulic lines. 6. Install the chain anchors. 7. Install the lifting chains. 8. Install the carriage. See masts section for checks and adjustments.
CHEVRON-STYLE PACKING The replacement seal kits for chevron-style packing have a single-lip seal and an aluminum spacer. The seal kits also have one or two backup rings. If one backup ring is in the seal kit, install it as shown in B of Figure 16. Two backup rings are installed as shown in C of Figure 16. Make sure the single-lip seal is always installed correctly against the direction of pressure. The installation of chevron-style packing on a piston is shown in Chevron-Style Packing Installation on Piston. The installation of chevron-style packing in a packing gland nut used at the top of the cylinder is shown in Chevron-Style Packing Installation in Packing Gland. There will be some variation in the design of the different lift cylinders. The principles of installation of the chevron-style packing is similar. Lubricate the parts with hydraulic oil or packing lubricant (Part No. 186061) before assembly.
4000 SRM 135
Lift Cylinder Repair
A. MANY EARLIER PRODUCTION LIFT TRUCKS WITH LESS THAN 7000 kg (15,000 lb) CAPACITY THAT HAVE CHEVRON-STYLE PACKING CAN BE CHANGED TO SINGLE-LIP SEALS. B. THE PARTS ARE INSTALLED IN THE ARRANGEMENT SHOWN. C. IF TWO BACKUP RINGS ARE IN THE SEAL KIT, THE PARTS ARE INSTALLED IN THE ARRANGEMENT SHOWN. 1. CHEVRON-STYLE PACKING 2. ALUMINUM SPACER
3. BACKUP RING 4. SINGLE-LIP SEAL ASSEMBLY
5. DIRECTION OF OIL PRESSURE
Figure 16. Chevron-Style Packing Replacement Seal Kits
Chevron-Style Packing Installation on Piston STEP 1. Lubricate the new O-ring with hydraulic oil and then install it on the piston end of the cylinder rod.
STEP 2. Install a new packing assembly on the piston half. The packing must extend approximately 3 mm (1/8 in.) beyond the end of the piston half.
1. THIS RING MUST EXTEND 3 mm (1/8 in.) BEYOND END OF PISTON HALF.
19
Lift Cylinder Repair
4000 SRM 135
STEP 3. Install the piston half and snap ring.
STEP 4. Install the nylon spacer.
STEP 5. Install the piston in the lift cylinder. Carefully push the piston and piston rod into the lift cylinder. Release the clamp on the packing when the packing moves past the threads of the cylinder.
1. PISTON 2. SPECIAL TOOL OR BAND CLAMP TO INSTALL PACKING
20
4000 SRM 135
Lift Cylinder Repair
Chevron-Style Packing Installation in Packing Gland STEP 1. Assemble the packing gland nut using new packing, O-ring, and backup ring.
1. PACKING ASSEMBLY 2. BACKUP RING 3. O-RING
4. PACKING RING MUST EXTEND 3 mm (1/8 in.) BEYOND EDGE OF BUSHING.
STEP 2. Assemble the gland nut using a new O-ring, backup ring, and inner seal.
NOTE: Install inner seal (if equipped). STEP 3. Install the bushing assembly and gland nut assembly in the rod.
21
Lift Cylinders for VISTA ® Masts
4000 SRM 135
STEP 4. Install a new wiper ring and spring on the retainer. Install the retainer against the packing gland nut. Lightly hit the retainer to move against the internal threads in the cylinder shell. Use a spanner to tighten the retainer.
1. O-RING
Lift Cylinders for VISTA ® Masts DESCRIPTION All lift cylinders for Vista ® masts are single-action hydraulic cylinders. The hydraulic force is applied only in one direction. When hydraulic oil enters one end of the lift cylinder, the hydraulic force extends the piston rod. When the force is removed, the weight of the carriage and inner mast causes the piston rod to retract. The most common maintenance problem is the repair of oil leaks. If the bore of the shell of the lift cylinder is damaged and cannot be repaired, the lift cylinder must be replaced. VISTA ® two-stage, three-stage, and four-stage masts have two main lift cylinders. The free-lift mast has two main lift cylinders and a shorter free-lift cylinder. See Figure 17 and Figure 18. Spacers are used in some cylinders to limit the stroke of the piston rod. Worn spacers must be replaced with the same size spacer. The free-lift cylinder has a single-lip seal on the piston to prevent hydraulic oil leaks past the piston and
22
retainer. The piston rod is a smaller diameter than the piston. During operation, some hydraulic oil will leak past the piston area to the rod end of the lift cylinder. Small leaks are permitted if the internal leak rate of the hydraulic system is not greater than the specification. An internal check valve is installed in the piston of the free-lift cylinders. When the piston rod extends, the pressure increases more quickly on any oil in the rod end of the lift cylinder. The hydraulic oil transf e rs through the check valve to the piston end of the free-lift cylinder. This action prevents hydraulic damage to the single lip seal and the wiper ring. See Figure 19.
Lowering Control Valve A lowering control valve is installed in the hydraulic line to the bases of the lift cylinders. See Figure 20. The lowering control valve permits easy entry of hydraulic oil into the cylinders, but gives a restriction when the rods retract. This restriction controls the
Lift Cylinders for VISTA ® Masts
4000 SRM 135
maximum speed at which a load on the forks can be lowered. The lowering control valve pre vents a load
on the forks from freely falling if a hydraulic hose breaks.
Figur e 17. Vista ® Masts Typical Lift Cylinders
23
Lift Cylinders for VISTA ® Masts
4000 SRM 135 Legend for Figure 17
1. 2. 3. 4. 5.
SHELL BEARING PISTON PISTON ROD SNAP RING
6. WASHER 7. INNER PISTON 8. CHECK VALVE 9. O-RING 10. SINGLE-LIP SEAL
11. BACKUP RING 12. WIPER SEAL 13. RETAINER
1. 2. 3. 4. 5. 6. 7.
SNAP RING INNER PISTON BEARING SINGLE-LIP SEAL BACKUP RING SPACER ROD
8. SHELL 9. O-RING 10. BACKUP RING 11. SEAL RING 12. RETAINER [TIGHTEN 340 to 410 N•m (250 to 300 lbf ft)] 13. WIPER SEAL
14. PISTON 15. 7.9 mm (0.31 in.) DIAMETER HOLE 16. WRENCH FLATS
Figure 18. Free-Lift Mast Main Lift Cylinder The lowering control valve includes the following parts: (1) valve body, (2) spring, (3) washer, (4) cylinder, (5) orifice sleeve, (6) plunger, and (7) main sleeve. The orifice sleeve position is controlled by oil flow. The plunger position is controlled by oil pressure and spring tension. During lifting, oil entering the lift cylinder goes through the center of the main sleeve to the large holes. The oil continues between the plunger and bore to move the orifice sleeve to the end of the plunger. The flange of the orifice sleeve is then aligned with the large part of the bore in the body. This alignment lets the oil flow around the orifice sleeve to the inlet port of the lift cylinder. During the lowering operation, oil from the lift cylinder moves the orifice sleeve. The sleeve moves away from the larger area of the bore in the valve body. This movement makes a restriction to the oil flow. When the pressure increases, the plunger begins to move against the spring. The movement begins to close the openings of the large holes in the main sleeve. Additional pressure will push the plunger against the main sleeve to close the large
24
holes completely. All the oil must go through the small holes to the center of the main sleeve. This restriction permits the piston rod to lower only at a maximum controlled speed.
REMOVE NOTE: Remove the carriage before removing the lift cylinder. See the procedure described in the Masts section. If the mast assembly must be removed for repairs, then remove the lift cylinders when the mast assembly is disassembled. When only the lift cylinders must be removed for repairs, then remove the lift cylinders from the mast as described in the following paragraphs. 1. Clean the area around the hydraulic fittings for the lift cylinders. Disconnect the fittings at the lift cylinders and put caps on the open lines. 2. On the free-lift mast, remove the capscrews, washers, and cylinder clamp from the mount for the free-lift cylinder. Remove the free-lift cylinder.
Lift Cylinders for VISTA ® Masts
4000 SRM 135 3.
4.
Remove the snap rings and washers from the top of each main lift cylinder. Remove the cylinder clamps near the top of each lift cylinder. Each cylinder clamp is fastened to the top crossmember of the inner mast by two capscrews and washers. Support the cylinder. Connect a crane to the top of the inner mast using chains. Raise the inner mast from the outer mast approximately 30 cm (12 in.). Disengage the piston rod ends of lift cylinders from the top crossmember of the inner mast. Remove the lift cylinders from the mount plates at the bottom of the outer mast.
DISASSEMBLE WARNING Use slings and a crane to handle and disassemble the lift cylinders of most lift trucks. Make sure that the crane and slings can lift the load correctly. See Table 2 for weight guide.
CAUTION Carefully disassemble and assemble the lift cylinders so that the piston rods and sliding surfaces are not damaged.
NOTE: Disassembly of the main lift cylinders and the free-lift cylinder is similar. All of the lift cylinders are disassembled from the rod end of the cylinder shell. 1. Loosen the retainer with a spanner. Disconnect the retainer from the shell. 2. Remove the protective cap from the inlet and slide the rod and piston assembly from the shell. Drain the hydraulic oil into a container.
NOTE: To remove the retainer, the piston rod and piston assembly must be disassembled if the lift cylinder is the type shown in Figure 18. Use the following procedure: a. Put a round bar through the 7.9 mm (0.31 in.) hole in the piston. Hold the rod in a vise or clamp so that it does not turn. Use the round bar and turn the threaded piston from the piston rod. b. If an adhesive was used on the threaded rod and piston, heat the rod to a maximum of 170 to 225 C (300 to 400 F) to loosen the adhesive.
A. INSTALLED
B. NOT INSTALLED
3. Remove the retainer from the piston rod. Remove and discard the O-rings, seals, and bearings.
1. PISTON AND ROD ASSEMBLY 2. CHECK VALVE 3. O-RING
4. INLET AND OUTLET PORT 5. SINGLE-LIP SEAL 6. O-RING 7. BACKUP RING
4. Remove the internal check valve from the base of the lift cylinder.
Figure 19. Internal Check Valve and Single-Lip Seal
5. Clean all the parts. Check the sliding surfaces for damage. Repair or replace any damaged parts.
25
Lift Cylinders for VISTA ® Masts
4000 SRM 135
ASSEMBLE NOTE: • Lubricate all internal parts of the lift cylinder with hydraulic oil during assembly. • Use new O-rings, seals, and bearings. Apply lubricant (hydraulic oil) during assembly. Packing lubricant (Part No. 186061) is also available. • Make sure the single-lip seal assemblies are installed with the O-ring toward the base of the lift cylinder. (See Figure 19.)
CAUTION A difficult and important step in assembling lift cylinders is the correct installation of the seals. Most lift cylinder maintenance is caused by seal leaks. 1.
Install the internal check valve, if installed. Make sure the arrow on the internal check valve is toward the base of the piston.
2. Install the wear ring, single lip seal, and backup ring onto the piston assembly. If a spacer sleeve is used, install it. Use shim material and a clamp as a guide to move the single-lip seal over the threads of the shell. 3. Carefully push the piston and rod assembly into the shell. Release the clamp on the seal when the seal travels past the threads of the shell.
NOTE: When a main lift cylinder of the type shown in Figure 18 is assembled, use the following procedure: a. Install the seal ring and wiper ring into the retainer. Assemble the retainer onto the piston rod. b. Install the piston to the threaded part of the piston rod. Use a round bar through the hole in the piston and tighten the piston to the piston rod. Hold the piston rod in a vise or clamp by the two flats on the top end of the piston rod.
A. FREE FLOW B. LIFTING
C. RESTRICTED FLOW D. LOWERING
1. 2. 3. 4.
5. ORIFICE SLEEVE 6. PLUNGER 7. MAIN SLEEVE
VALVE BODY SPRING WASHER CYLINDER
Figure 20. Lowering Control Valve
26
4000 SRM 135
NOTE: Do not use an adhesive on the threads of the piston rod and piston. 4. Install the seal, O-ring, wear ring, and wiper ring in the retainer. If the wiper seal has a spring for a backup ring, the spring must be toward the base of the lift cylinder. 5.
Carefully install the retainer on the piston rod.
6.
Engage the threads and tighten the retainer in the shell until it is tight. Use a correct spanner. Do not hit the retainer with a hammer and driver.
7.
Install the lowering control valve. Make sure the special washer and the spring are installed correctly. A wrong installation can cause the load to lower too fast.
Lift Cylinders for VISTA ® Masts
of the inner mast. Install the washers and snap rings, or other locking device, at the top of the lift cylinders. Install the cylinder clamps near the top of each cylinder. Fasten the clamps, if used, to the top crossmember of the outer mast with the capscrews and washers. 2. Install the lowering control valve on the outer mast. Connect the hydraulic lines and fittings between the lowering control valve and the lift cylinders. 3. Install the chain sheaves and brackets. Connect the lift chains to the chain anchors on the inner mast. Fasten wires between the ends of the lift chains so that they can be controlled during installation of the carriage. 4. Install the carriage. Connect the lift chains.
INSTALL
Free-Lift Cylinder
Main Lift Cylinders
1. When the inner mast is lowered, install the freelift cylinder in the inner mast. A pin in the base of the lift cylinder will fit into the cylinder mount at the base of the inner mast. Fasten the upper end of the cylinder to the center crossmember with the bracket, washers, and capscrews. Install the chain sheave and brackets to the top of the free-lift piston rod.
WARNING Connect slings and a crane to the top of the inner mast [and intermediate mast(s), if it is a 3-stage (4-stage) mast] using chains. If it is a 3-stage mast, make sure that all masts are fastened together. Make sure that the chains will not damage the sheaves, tubing or other parts of the mast. Make sure the crane and slings can lift the load correctly. See Table 2 for weight guide. 1.
Install the main lift cylinders to the mounts at the base of the outer mast. Use a crane and lower the inner mast to engage the piston rods of the lift cylinders to the holes in the top crossmember
2. Install the tubes and fittings at the bottom of the main lift cylinders. Install the lowering control valve. Install the hydraulic fitting in the end of the rod at the top of the left main cylinder. Install the tube between the top of the main lift cylinder and the base of the free-lift cylinder. 3. Install the carriage. Install the lift chain.
27
Lift System Leak Check
4000 SRM 135
Lift System Leak Check WARNING Never allow anyone under a raised carriage. Do not put any part of your body through the lift mechanism unless all parts of the mast are completely lowered and the engine is stopped. Before making any repairs, use blocks and chains on the mast and carriage so that they cannot move. Make sure the moving parts are attached to the parts that cannot move. Do not try to find hydraulic leaks by putting hydraulic components under pressure. Hydraulic oil can be injected into the body by pressure. During the test procedures for the hydraulic system, fasten the load to the carriage with chains to prevent it from falling. Keep all personnel away from the lift truck during the tests. 1.
Operate the hydraulic system. Put a capacity load on the forks and raise and lower the load several times. Lower the load and tilt the mast forward and backward several times. Check for leaks.
2.
Raise the carriage and the load 1 m (3 ft). If the carriage lowers slowly with the control valve in a
28
neutral position, there are leaks inside the hydraulic system. The maximum speed that the carriage is allowed to lower is 50 mm (2 in.) per 10 minutes when the hydraulic oil is 30 C (90 F). If the oil temperature is 70 C (160 F), the maximum speed that the carriage can lower is 150 mm (6 in.) per 10 minutes. 3. Check the lif t cylinder for internal leaks. Remove the load from the forks. Install a gate valve in the supply line between the main control valve and the mast. Put a capacity load on the forks again. Raise the carriage 1 m (3 ft). Close the gatevalve. If the carriage or mast lower slowly, the seals in the lift cylinders have leaks. 4. If the carriage does not move, open the gate valve and check the movement again. If the carriage lowers when the gate valve is open, check for leaks in the hydraulic lines and fittings. If no leaks are found, the main control valve can have a defect. Remove the load from the forks. NOTE: See the procedures in the mast repair sections for lift chain adjustments, mast adjustments, carriage adjustment, and header hose roller adjustment.
4000 SRM 135
Specifications
Specifications Table 2. Cylinder Retainer Torque Specifications and Weight Guide Rod Diameter
Typical Outer Retainer Torque Values
mm
N•m
in.
Lifting Mechanism
lbf ft
One-Stage Cylinders for Lift Trucks with Less than 7000 kg (15,000 lb) Capacity 57.2
2.25
373-441
275-325
63.5
2.50
203-271
150-200
69.9
2.75
373-441
275-325
76.2
3.00
407-475
300-350
81.3
3.20
407-475
300-350
88.9
3.50
475-452
350-400
101.6
4.00
407-475
300-350
114.3
4.50
610-678
450-500
Use crane and slings with at least 500 kg (1000 lb) capacity to lift the cylinder.
One-Stage Cylinders for Lift Trucks with More than 7000 kg (15,000 lb) Capacity 108.0
4.25
113.4
5.25
241.3
9.50
254.0
10.00
Tighten retainer or packing gland nut. Oil leakage is not controlled by the torque on the retainer.
Use crane and slings with at least 1000 kg (2000 lb) capacity to lift the cylinder.
Use crane and slings with at least 2000 kg (4000 lb) capacity to lift the cylinder.
Two-Stage Cylinders for Lift Trucks with Less than 5000 kg (10,000 lb) Capacity 82.6
3.25
373-509
325-375
95.3
3.75
271-305
200-225
101.6
4.00
271-339
200-250
114.3
4.50
339-407
250-300
122.0
5.00
407-475
300-350
Use crane and slings with at least 500 kg (1000 lb) capacity to lift the cylinder.
Inner retainer torque value is 122 N•m (90 lbf ft).
29
Troubleshooting
4000 SRM 135
Troubleshooting PROBLEM No movement of lift cylinders or tilt cylinders.
Slow movement of lift or tilt cylinders.
Rough movement of themast assembly.
30
POSSIBLE CAUSE
PROCEDURE OR ACTION
Pilot line(s) to control valve are disconnected or leaking.
Tighten or connect fittings.
No oil or not enough oil in the hydraulic tank.
Fill tank. Check for leaks.
Relief valve(s) not set correctly.
Adjust or install new relief valve.
Hydraulic pump does not operate or has damage.
Repair or install new pump.
Remote control valve does not operate.
Check and repair valve.
No oil or not enough oil to lift or tilt cylinders.
Fill tank. Check for leaks.
Cylinders have internal or external leaks.
Repair leaks. Install new parts.
Relief valve is not set correctly.
Adjust or install new relief valve.
There is a restriction in a hydraulic line.
Remove restriction. parts.
Load is more than capacity.
Reduce load.
There is air in the hydraulic system.
Remove air. Check for loose connections or breaks in lines.
Lift cylinder(s) is damaged.
Repair or install new lift cylinder.
Mast weldments are damaged or not aligned.
Align weldments. Install new parts.
Mast weldments are not lubricated.
Lubricate correctly.
Load rollers or bearing blocks are damaged or not adjusted correctly.
Repair or adjust the parts.
Lift chains are damaged.
Replace lift chains.
Install new
