BEARING REPL.G 4F9579 - Caterpillar

Machine without a Boom Lowering Control Valve
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 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 g00101544
Remove four bolts (1), four washers (2), and the cover (3) from the top of the hydraulic tank.
Illustration 2 g00101546
Slowly loosen fill/vent plug (4) on the top of the hydraulic tank until internal pressure in the hydraulic tank has been completely relieved. Remove fill/vent plug (4) .
Loosen clamp (6) and disconnect hose (5) from the side of the hydraulic tank.
Illustration 3 g00101548
Connect an end of hose (5) to screw (7 ). Put the other end of hose (5) into the filler plug opening.
Slowly loosen screw (7) by a maximum of 1/2 turn. This allows the hydraulic oil in the boom circuit to drain into the hydraulic tank. The boom will now start to lower.
Make sure that the work tool has lowered all the way to the ground. Tighten screw (7) to a torque of 13 2 N m (9 1 lb ft).
Disconnect hose (5) from screw (7). Do not allow the oil that is contained in hose (5) to spill.
Connect hose (5) to the original position on the hydraulic tank and install fill/vent plug (4) securely.After completion of the manual boom lowering, make necessary repairs before you operate the machine again.Machine with a Boom Lowering Control Valve
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. Use the following procedure if the machine is equipped with a boom lowering control valve.
Illustration 4 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 5 g00101604
Loosen locknut (1) .
Slowly turn check valve (2) counterclockwise until the check valve stops. The boom will lower to the ground.
Make sure that the work tool has been completely lowered onto the ground. Turn check valve (2) to the Closed position.
Tighten locknut (1) to a torque of 55 10 N m (41 7 lb ft).
Before you begin operating the machine, make any necessary repairs.For additional information, consult your Caterpillar dealer.