322B Excavator Hydraulic System Caterpillar

Illustration 1	g00372122
Pump Compartment (27) Setscrew (28) Locknut (29) Setscrew (30) Locknut

Note: Use the same procedure for both pumps. Use locknut (28) and setscrew (27) for the upper pump adjustment. Use locknut (30) and setscrew (29) for the lower pump adjustment.

1. In order to adjust the upper pump, loosen locknut (28) .

2. Turn setscrew (27) until the negative flow rate is adjusted to the correct specification.

   Note: A clockwise adjustment of setscrew (27) and setscrew (29) decreases the flow rate. A counterclockwise adjustment increases the flow rate. A quarter turn of setscrew (27) and setscrew (29) will change the flow rate approximately 2.0 L/min (0.5 US gpm) at a system pressure of 2200 kPa (320 psi).

3. Tighten locknut (28) to a torque of 12 ± 3 N·m (9 ± 2 lb ft).

4. Adjust the lower pump. Use locknut (30) and setscrew (29) instead of locknut (28) and setscrew (27) to adjust the lower pump.