345B Excavator Equipment Lowering with Engine Stopped Caterpillar

In order to lower the boom, place 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. Use the following method to lower the boom.

Note: The boom can be lowered within 60 seconds after turning off the engine if the accumulator is charged. After 60 seconds, the hydraulic electronic control module will shut off and the joysticks will be disabled. The hydraulic lockout control must be in the UNLOCKED position.

Machine with a Boom Lowering Control Valve

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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, causing possible injury or death. To avoid possible injury or death, be sure no one is under or near the work tool 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. Use the following procedure if the machine is equipped with a boom lowering control valve.

Illustration 1	g00101574

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 AVSpare dealer.