BEARING 0979283 - Caterpillar

Reference
Reference: Operation and Maintenance Manual, SEBU9417, System Pressure ReleaseIntroduction
The accumulator stores hydraulic oil pressure that can be used to lower the implements when the engine is off. The accumulator is on the pilot manifold.The following procedure will determine if the accumulator for the pilot system is charged to the appropriate pressure.Required Tools
Illustration 1 g06312833
Tooling (B)
Table 3
Tool Item Qty Part Number Description
T1 T1a 1 8T-0856 Pressure Gauge
(0 to 6,000 kPa (0 to 870 psi))
T1b 1 6V-3989 Fitting
T1c 2 6V-4143 Quick Connect Coupler
T1d 1 177-7860 Hose As (10 ft) Test Preparation - Accumulator Leak Down
Move the machine to a smooth horizontal location.
Engage the parking brake.
Lower all the implements.
Stop the engine.
Turn the key to the ON position. Make sure that the implement lockout switch is turned to the UNLOCKED position.Reference: Refer to the Operation and Maintenance Manual, SEBU9417, System Pressure Release for correct procedure to release any pressure.
Illustration 2 g02454857
(1) Implement valve stack
(HPS) Pressure tap
(2) Pilot manifold
(3) Accumulator
(AP) Pressure tap
Attach tooling (T1) to pressure tap (AP).Test Procedure - Accumulator Pilot Oil Pressure Leak Down
Start the engine. Warm the hydraulic oil to a minimum temperature of 65° C (150° F).
Record the pressure reading on pressure tap (AP).
Stop the engine. Turn the key to the ON position but do not start the machine.
With the implement lockout switch in the UNLOCKED position, record the pressure reading at pressure tap (AP).
The pressure reading should not drop more than 500 kPa (73 psi) in 2 minutes. If a pressure drop greater than 500 kPa (73 psi) occurs, the pilot oil system should be checked for excessive leakage.Adjustment Procedure - Pressure Leak Down
There are no adjustments that can be made to reduce pressure leaks in the system. Investigate the components of the charging system to determine the cause of the system leakage.Test Preparation - Accumulator Charge Pressure
Move the machine to a smooth horizontal location.
Engage the parking brake.
Lower all the implements.
Stop the engine.
Turn the key to the ON position. Make sure that the implement lockout switch is turned to the UNLOCKED position.Reference: Refer to the Operation and Maintenance Manual, SEBU9417, System Pressure Release for correct procedure to release any pressure.
Illustration 3 g02454857
(1) Implement valve stack
(HPS) Pressure tap
(2) Pilot manifold
(3) Accumulator
(AP) Pressure tap
Attach tooling (T1) to pressure tap (AP) on pilot manifold (2).Test Procedure - Accumulator Charge Pressure
Start the engine. Warm the hydraulic oil to a minimum temperature of 65° C (150° F).
Operate the engine at HIGH IDLE.
Exercise the implement hydraulics. At the accumulator, the pilot pressure at tooling (AP) should be greater than 2500 kPa (363 psi).
Shut off the engine. Turn the key to the ON position. The accumulator charge pressure should remain steady until an implement control is exercised.
With the implement lockout switch in the UNLOCKED position, move the implement control out of the HOLD position in any direction to actuate a function. Return the handle to the hold position between activations of the handle. Quick movement of the handle should increase the accuracy of this test.
With the handle in the HOLD position between activations,