Komatsu PC450-8, Operation & Maintenance Manual

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MAINTENANCE PROCEDURE
MAINTENANCE
4-78
4. Turn the starting switch to the ON position (B).
5. With the lock lever at the FREE position (F), operate the
work equipment control levers fully in the LOWER direction
and check that the work equipment is lowered to the
ground.
6. If the work equipment goes down under its weight and con-
tacts the ground, the accumulator is normal.
If the work equipment does not go down or stops in mid-
way, the charged pressure of the gas in the accumulator
for the hydraulic circuit has probably dropped.
Please contact your Komatsu distributor for inspection.
7. This completes the inspection. After completion of the inspection, set the lock lever to the LOCK position and
turn the starting switch to the OFF position.
METHOD OF RELEASING PRESSURE IN HYDRAULIC CIRCUIT 4
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 posi-
tion (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.