322B Excavator Hydraulic System Caterpillar

Test

1. Position the machine on level ground.

2. Stop the engine.

3. Release the pressure in the hydraulic system. Refer to Testing And Adjusting, "Hydraulic System Pressure - Release".

Show/hide table



Illustration 1	g00372754
Pump compartment (1) Pressure tap (power shift pressure) (2) Pressure tap (upper pump delivery pressure) (3) Pressure tap (lower pump delivery pressure)

4. Connect a 60000 kPa (8700 psi) pressure gauge to pressure tap (3) .

Show/hide table



Illustration 2	g00374832
Swing motor (26) Connector (27) Solenoid valve for swing parking brake

5. Disconnect connector (26) from the solenoid valve for swing parking brake (27) .

6. Start the engine.

7. Place the machine controls at the following settings: Power Mode, engine speed dial "10" and AEC switch OFF.

   Reference: Make reference to Testing And Adjusting, "Operational Checks" for engine rpm settings.

8. Increase the hydraulic oil temperature to 55° ± 5°C (131° ± 9°F).

   Note: Move the swing control lever slowly and ensure that the swing parking brake is operating properly.

Adjust

Show/hide table



Illustration 3	g00374833
Swing motor (22) Adjustment plug (23) Locknut (24) Relief valve (right swing) (25) Relief valve (left swing)

1. Slowly move the swing control lever for a full RIGHT swing operation and check the pressure for relief valve (24) at pressure tap (3) .

2. Return the swing control lever to the NEUTRAL position.

3. Loosen locknut (23). Turn adjustment plug (22) until the pressure gauge reading at pressure tap (3) is 27500 ± 980 kPa (4000 ± 140 psi).

   Note: Turning adjustment plug (22) clockwise increases the pressure. Turning adjustment plug (22) counterclockwise decreases the pressure.

4. Tighten locknut (23) to a torque of 160 ± 30 N·m (120 ± 22 lb ft).

5. Slowly move the swing control lever for a full LEFT swing operation and check the pressure for relief valve (25) at pressure tap (3) .

6. Return the swing control lever to the NEUTRAL position.

7. Adjust relief valve (25) for left swing in the same manner as relief valve (24) for right swing.

   Note: Always make final pressure adjustments on pressure rise.