Komatsu H70051 Series Operation & Maintenance Manual page 377

MAINTENANCE
10. Remove the bolts (9) (4 pieces) and remove the cover
(10).
11. Hold the top of rod (11) and pull it up to take out the strain-
er (12).
12. Remove any dirt stuck to the strainer (12), then wash it in
flushing oil.
If the strainer (12) is damaged, replace it with a new one.
13. Install the strainer (12) to the inside of the tank.
14. While pressing the cover (10), tighten the mounting bolts
(9) evenly.
When doing this, if the O-ring (13) of the cover is damaged
or deteriorated, replace it.
15. Refill with the specified quantity of hydraulic oil through oil
filler port (F), then install the cap.
16. Check the hydraulic oil level.
If the oil level is between H and L of sight gauge (G), it is
proper.
17. Run the engine at low idle, and extend and retract each of
the steering, bucket, and boom cylinders 4 to 5 times, tak-
ing care not to move them to the stroke end (stop them ap-
proximately 100 mm short of the stroke end).
NOTICE
If the engine is run at high speed immediately after the
startup or a cylinder is pushed up to its stroke end, air
taken inside the cylinder may cause damage to the
piston packing, etc.
18. Extend and retract each of the steering, bucket, and boom
cylinders to the stroke end 3 to 4 times.
19. Stop the engine, then loosen the cap of the oil filler port
(F).
20. Bleed air from the hydraulic tank. After bleeding air, tighten
the cap of the oil filler port (F).
21. Bleed air while running the engine at low idle.
22. Check the hydraulic oil level.
If the oil level is between H and L of sight gauge (G), it is
proper.
23. Increase the engine speed, and extend and retract each of
the steering, bucket, and boom cylinders 4 to 5 times, tak-
ing care not to move them to the stroke end (stop them approximately 100 mm {3.9 in} short of the stroke
end).
MAINTENANCE PROCEDURE
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