Komatsu PC220LC -8 Operation & Maintenance Manual page 343

MAINTENANCE PROCEDURE
METHOD OF RELEASING PRESSURE IN HYDRAULIC CIRCUIT
1. Place the work equipment on the ground. Close the crusher attachment jaws, etc.
2. Operate the work equipment lock lever to the LOCK position.
3. Insert the lock pin for the attachment control pedal in position
(c) where it is possible to operate the pedal.
(If equipped)
Carry out Steps 4 - 6 within 15 seconds.
When the engine is stopped, the pressure in the accumulator gradually goes down. For this reason, the release can
only be carried out immediately after the engine is stopped.
4. Stop the engine.
5. Turn the starting switch to the ON position (B).
6. Set lock lever to FREE position (F), then operate the work
equipment control levers and the attachment control pedal (if
equipped) fully to the front, rear, left, and right to release the
pressure in the control circuit.
7. Set the lock lever to the LOCK position, then turn the starting switch to the OFF position.
8. Insert the lock pin in position (a) so that the attachment control
pedal cannot be operated.
(If equipped)
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MAINTENANCE