Komatsu PC2000-8 BACKHOE, Operation & Maintenance Manual

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MAINTENANCE PROCEDURE
MAINTENANCE
4-56
BLEEDING AIR FROM MAIN VALVE PILOT PIPING
After the removal and installation of the main valve and the disconnection and connection of the PPC hose, bleed
air from the pilot selector valve circuit in the following manner.
REMARK
If air is not bled at all or bled but insufficiently, there is a possibility of a time lag while in the operation or an abnor-
mal noise from the PPC lever, so be sure to follow the air bleeding instructions.
1. Start up the engine and loosen bleeder (A).
The bleeder is provided at the joint of the main valve spring
casing (at 28 spots in total).
2. Operate each actuator while keeping the engine running at
low idling, check that oil free of air bubbles begins to flow
out of bleeder (A) and then tighten bleeder (A).
Tightening torque: 8.8 - 9.8 Nm (0.9 - 1.0 kgm)
REMARK
Air bleeding can be achieved with fine operation of each lever to the extent that each hydraulic switch turns on (ON
lights up).