322B Excavator Hydraulic System Caterpillar

Adjust the pump output flow if the flow test results differ greatly from the specifications.

Pump Output Flow Adjustment

Illustration 1	g00372593
Pump compartment (23) Locknut (24) Setscrew (25) Locknut (26) Setscrew

Adjust the flow of the upper pump.

1. Loosen locknut (23) .

2. Turning setscrew (24) clockwise will increase the output flow of the pump. Turning setscrew (24) counterclockwise will decrease the output flow of the pump. A 1/4 turn of setscrew (24) will change the output flow of the pump at the following pressures.

   1. The pressure range of the first regulator spring is 14300 kPa (2050 psi) to 21300 kPa (3100 psi). Output flow of the pump will change approximately 22 L/min (5.8 US gpm) if the output flow is adjusted in this pressure range.

   2. The pressure range of the second regulator spring is 21300 kPa (3100 psi) to 34300 kPa (4950 psi). Output flow of the pump will change approximately 8 L/min (2.1 US gpm) if the output flow is adjusted in this pressure range.

3. Tighten locknut (23) to a torque of 12 ± 3 N·m (9 ± 2 lb ft).

4. Adjust the lower pump. Use locknut (25) and setscrew (26) instead of locknut (23) and setscrew (24) to adjust the lower pump. Repeat Steps 1 through 3.

Adjustment of the Maximum Output Flow of the Pump

Illustration 2	g00372653
Pump compartment (27) Locknut (28) Setscrew (29) Locknut (30) Setscrew

Adjust the maximum output flow of the upper pump.

1. Loosen locknut (27) .

2. In order to adjust maximum output flow, turn setscrew (28). Turning setscrew (28) clockwise will decrease the maximum output flow of the pump. Turning setscrew (28) counterclockwise will increase the maximum output flow of the pump. When setscrew (28) is turned by 90 degrees, the flow changes approximately 1.5 L/min (0.4 US gpm).

3. Tighten locknut (27) to a torque of 100 ± 20 N·m (75 ± 15 lb ft).

4. Adjust the maximum output flow of the lower pump. Use locknut (29) and setscrew (30) instead of locknut (27) and setscrew (28). Repeat Steps 1 through 3.