W330B Material Handler Caterpillar

To lower the boom, turn the engine start switch to the ON position and place the lever for the hydraulic lockout control in the UNLOCKED position. Move the joystick to the Boom Lower position. If the accumulator is still charged, the boom will lower.

If the boom does not lower, the accumulator is empty.

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Boom load may cause cylinder oil pressure to reach relief pressure of the boom lowering control device when the boom is supported by one cylinder. Boom can lower suddenly. Be sure no one is under or near the implements before manually lowering the boom. Keep all personnel away from the boom drop area when lowering the boom with the engine stopped.

If the engine is shut down or the hydraulic system is disabled, the operator can still lower the boom.

Illustration 1	g00609556

The boom lowering control valve is at the back of the base of the boom. The boom lowering control valve allows the operator to manually lower the boom if the engine is stopped. The boom lowering control valve also ensures that the boom does not fall suddenly if there is an oil leak in the hydraulic line of the boom.

Illustration 2	g00101604

1. Loosen locknut (1) .

2. Slowly turn check valve (2) counterclockwise until the check valve stops. The boom will lower to the ground.

3. Make sure that the implement has been completely lowered onto the ground. Turn check valve (2) to the Closed position.

4. Tighten locknut (1) to a torque of 55 ± 10 N·m (41 ± 7 lb ft).

5. Before you begin operating the machine, make any necessary repairs.

For additional information, consult your Caterpillar dealer.