GEAR-OIL PUMP DRIVE 1110329 - Caterpillar

Machine Without a Boom Lowering Control Valve
Be sure no one is under or near the work tools before manually lowering the boom. Keep all personnel away from the boom drop area when lowering the boom with the engine stopped in order to avoid possible personal injury.
When you must manually lower the boom due to engine shutdown, use the following procedure.Note: Keep all personnel away from the boom when you are lowering the boom.
Illustration 1 g00806973
(1) Locknut (2) Screw
Slowly loosen locknut (1) .
Loosen screw (2) to a maximum of 1/2 turn. The boom will now start to lower.
After the work tool has completely lowered to the ground, tighten the screw and the locknut.
Consult your Caterpillar dealer and make any necessary repairs.After completion of the manual boom lowering, make necessary repairs before you operate the machine again.Machine With a Boom Lowering Control Valve (If Equipped)
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 stopped 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 2 g00609005
(1) Locknut (2) PistonThe boom lowering control valve (if equipped) is installed on each of the boom cylinders. The boom lowering control valves allow the operator to manually lower the boom if the engine is stopped. The boom lowering control valves also prevent a sudden drop of the boom if there is an oil leak in the hydraulic line of the boom.
Loosen locknut (1) of one boom lowering control valve.
Slowly turn piston (2) counterclockwise until the piston stops. The boom will lower to the ground.
Make sure that the work tool has been completely lowered onto the ground. Tighten piston (2) .
Tighten locknut (1) to a torque of 55 10 N m (41 7 lb ft).
Before you put the machine into operation, make any necessary repairs.For additional information, consult your Caterpillar dealer.