Hyster Forklift HR 45-27

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.

Upload a photo of the completed task

!WARNING: Cleaning solvents can be flammable and toxic and can cause skin irritation. When using cleaning solvents, always follow the solvent manufacturer’s recommended safety precautions.

Compressed air can move particles and cause injury to the user or to other personnel. Verify compressed air path is away from all personnel. Wear eye protection.

Clean cartridge valve in solvent and carefully dry the parts with compressed air.

Inspect the bores for damage. If there are scratches or other damage, the load holding valve must be replaced.

Inspect the fittings, O-rings, and check valves for damage. Replace damaged parts.

Sign off on the Derricking Circuit Maintenance

NOTE: The relief valves in the main manifold, main control valve, and flow amplifier are adjustable. If a relief pressure is not within specifications, adjust the relief valve.

Upload a photo of the correct gauge used on the check ports as per Table 2

Enter the temperature of hydraulic oil

Is the pressure gauge according to the specifications shown in Table 3?

To adjust a relief valve setting, remove cap. Loosen lock nut and use an Allen wrench to turn adjuster screw. Turn adjuster screw clockwise to increase pressure.

To lower pressure, first lower pressure below required value by turning adjuster screw counterclockwise and then increase pressure to required level. When relief pressure is correct, tighten lock nut and install cap.

Is the setting correct after tightening the lock nut?

During tightening the lock nut, the setting can be influenced. Adjust again, if necessary.

Sign off on the relief valve check

!WARNING: Lower boom completely before working on control valve or hydraulic system. The boom can lower suddenly and cause injury if the boom is not lowered. This procedure will make sure that the boom cannot lower suddenly and cause injury or death.

!NOTE: All valves, and other associated items installed on the load holding valve can be replaced. Before removal of any part, check that the area is clean and protected against dirt and fluid contamination.

Place the truck on a solid and level surface.

Lower boom and close the shutoff valves at the bottom of the hydraulic tank platform.

!WARNING: Move all control levers back and forth a minimum of 20 times to remove all hydraulic pressure from pilot system.

Put tags for identification on electrical wires. Disconnect the electrical wires from the load holding valve.

Put tags for identification on hydraulic lines. Disconnect the hydraulic lines from the load holding valve. Put caps on the open lines, ports or other connectors.

Remove the four capscrews that fasten the load holding valve to the rear side of the outer boom.

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