Komatsu PC88MR-10 Shop Manual page 401

a Since the PC valve is a decentered type, the
rotating direction (clockwise or
counterclockwise) to increase the absorption
torque cannot be stable. Adjust it by
monitoring the engine speed.
3. Tighten lock nut (5).
Lock nut:
29.4 to 39.2 Nm {3.0 to 4.0 kgm}
4. After finishing adjustment, check again that the
pump control pressure (the inlet pressure of
servo piston) is normal according to the
preceding check procedure.
PC88MR-10
30 Testing and adjusting
Hydraulic system
30-51