Komatsu PC2000-8 BACKHOE, Operation & Maintenance Manual

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MAINTENANCE
MAINTENANCE PROCEDURE
4-99
CHECK GAS PRESSURE IN ACCUMULATOR FOR OPERATION CONTROL CIRCUIT 4
NOTICE
If the nitrogen gas charge pressure in the accumulator is low and operations are continued, it will become
impossible to release the remaining pressure inside the hydraulic circuit if a failure occurs on the
machine.
Check the nitrogen gas charge pressure as follows.
1. Stop the engine, turn the engine starting switch to the ON position, move the lock lever to the FREE position
and operate boom LOWER.
2. Check that the tip of the bucket drops at least 1 m.
If the tip of the bucket drops less than 1 m, the charge pressure inside the accumulator is low, so contact your
Komatsu distributor.
CHECK WELDED STRUCTURE 4
(Color check)
It is easy to use a color check to check visibly for cracks in welded structures. After the first 4000 hour inspection,
check the revolving frame, center frame, boom, and arm every 1000 hours.
In particular, carry out a color check on the important check points (marked with a circle).
The procedure for the color check is as follows.
1. Prepare the materials needed for the color check. (Detergent, penetrating agent, developing solution)
2. Spray with detergent and wash to remove all the dirt and oil from the place to be checked.
3. After washing, dry the area, then spray with penetrating agent and leave for 5 - 20 minutes.
4. Spray with detergent, then clean the surface with a cloth.
5. Clean the surface again, then spray with developing solution.
6. Leave for 15 - 20 minutes, then check visually for cracks.
If there are any cracks, color can be seen.
7. If there are any cracks, carry out the repair procedure to repair.