Hyster Forklift RS46-37IH

!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.

Is the truck placed on a solid and level surface?

Is the boom lowered and the shutoff valves at the bottom of the hydraulic tank platform closed?

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

Are tags for identification put on electrical wires? Are the electrical wires disconnected from the load holding valve?

Are tags for identification put on hydraulic lines? Are the hydraulic lines disconnected from the load holding valve? Are caps put on the open lines, ports or other connectors?

Are the four capscrews that fasten the load holding valve to the derricking cylinder removed?

!NOTE: Never remove the safety stand pipe to avoid dirt from entering the hydraulic system.

Engine shut down and parking brake applied

Yellow button on the indicator pressed to release pressure

Cap loosened by turning counterclockwise

Inside of the housing cleaned with solvent

Cap installed by turning clockwise

Engine started and operation of indicator checked

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: 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. Make sure compressed air path is away from all personnel. Wear eye protection.

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

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

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

Sign off on the Cab Manifold Maintenance

Two methods are given for checking the volume of flow from the hydraulic pump. The first method uses a flow meter, a pressure gauge, and a needle valve. The second method uses a needle valve, a pressure gauge, a container, and a timer.

1. If the flow meter is available, install flow meter between needle valve and outlet port of pump. See Figure 5. Pressure gauge must be between needle valve and pump. Make a separate check for each system.

When hydraulic oil is at operating temperature, run engine at 2100 rpm with no load on hydraulic system. Note reading of flow meter. Compare output rate of pump with specification found in the Specifications section.

!WARNING: Hydraulic oil can be hot. Do not touch oil during tests.

2. Run engine at high limit. Slowly close needle valve until gauge indicates a pressure just below specification for relief valve setting. Pump out- put at high pressure must be within 25% of out- put with no load. If output at high pressure is less than 75% of low pressure output, pump has a problem.

1. Another method of checking pump output is to measure the amount of oil moved in a given amount of time. See Figure 6. Run engine until oil is 55 to 65 C (130 to 150 F).

Disconnect line from outlet port of pump. Install a 0 to 21 MPa (0 to 3050 psi) pressure gauge on a tee fitting connected to a hose from outlet port. Install needle valve on end of hose.