Hyster Forklift HR 45-31

NOTE: Only use plugs that have been cleaned in solvent.

NOTE: In the event that seals are missing, check manifold for missing seals and remove.

NOTE: Cartridge valves are not field serviceable with exception of external seals and electrical solenoids. In event of a defective component, completely replace valve.

NOTE: Check load holding valve for cracks. If there are cracks in load holding valve, the load holding valve must be replaced.

The valve seals are serviceable parts of the load holding valve. Use the following procedures for repair:

Unscrew the cartridge valve from the load holding valve. See Figure 9.

Check that all seals are attached to cartridge valve.

Install a temporary plug in place of cartridge valve.

Sign off on the Boom Extension Circuit Disassemble

Lower boom completely and close shutoff valves on the bottom of the hydraulic tank

Shut down the engine and apply the parking brake

Apply brakes minimum 10 times to relieve hydraulic pressure

Drain hydraulic oil from hydraulic tank

Remove bolts retaining the inspection cover

Remove suction filters by turning each filter counterclockwise

Install new suction filters by turning each filter clockwise

Warning: Each pump assembly weighs approximately 45 kg (100 lb) and can cause injury or damage if it falls.

Clean flange of the pump assembly and mounting surface on the torque converting housing.

Install pump assembly on the torque converting housing. Use a sealant on the flange of the pump assembly. Tighten capscrews to 90 N•m (66 lbf ft).

Connect the hydraulic hoses to the pump assembly. Tighten capscrews for flange of high-pressure hoses to 190 N•m (140 lbf ft). If necessary, tighten capscrews for flange of suction hose to 88 N•m (65 lbf ft).

Repeat Step 1 through Step 3 for the second hydraulic pump.

Warning: Never start the engine when pumps are not filled with oil. Verify that the pumps are filled with oil by removing the drain line and fill the pump chamber by using the drain opening. Otherwise this can cause serious damage and loss of durability to the pump(s).

Caution: Never start the engine with closed shutoff valves. Open the shutoff valves before starting the engine to prevent damage to hydraulic components.

Start engine and operate hydraulic system. Check that functions work correctly.

Warning: Do not try to locate hydraulic leaks by putting hands on pressurized hydraulic components. Hydraulic oil can be injected into the body by pressure.

!WARNING: Cleaning solvents are flammable and toxic and can cause skin irritation. When using cleaning solvents, always follow the solvent manufacturer’s recommended safety procedures. Wear protective goggles or a face shield to prevent eye injuries.

Clean all parts of pump with solvent. Use compressed air to dry parts. Do not use a cloth to dry parts. Pieces of cloth can cause restrictions in hydraulic system.

Inspect gear assemblies and housing parts for wear and damage. Replace a damaged or worn hydraulic pump. If gears are replaced, they must be replaced as matched sets.

!NOTE: Some pump bodies will show gear marks where the gears rotate because of the small clearances between parts. These gear marks do not indicate a worn or damaged pump unless the pump will not supply the volume and pressure shown in the Specifications.

Sign off on the hydraulic pump maintenance

Component/valve lubricated with clean hydraulic oil

Component/valve or switch installed and torqued to value listed in the Torque Specifications

Sign off on the Cab Manifold Assemble