Komatsu WA380-6 Operation & Maintenance Manual page 295

SERVICE PROCEDURE SERVICE PROCEDURE
7. Remove mounting bolt (5) of filter cover (4) at the top of the
tank, then remove the cover.
When doing this, the cover may fly off under the force of spring
(6), so keep the cover pressed down when removing the bolts.
8. Remove spring (6) and bypass valve (7), then take out element
(8).
9. Check that there is no foreign material inside the tank, then
clean it.
10. Install new element (8), then set bypass valve (7), spring (6),
and cover (4) on the tank.
When doing this, check the cover O-ring. If it is damaged or
deteriorated, replace it.
11. Remove 6 bolts (10), then remove cover (9).
12. Pull the top of rod (11) from the top and remove strainer (12).
13. Remove any dirt stuck to strainer (12), then wash it in flushing
oil. If strainer (12) is damaged, replace it with a new part.
14. When installing the cover bolts, push down the cover and tighten the bolts evenly.
15. Add engine oil through oil filler port (F) to the specified level, then install cap (F).
16. Check that the hydraulic oil is at the standard level. For details, see "CHECK OIL LEVEL IN HYDRAULIC TANK,
ADD OIL (PAGE 4-40)".
17. Run the engine at low idle, and extend and retract the steering, bucket, and lift arm cylinders 4 to 5 times. Be
careful not to operate the cylinder to the end of its stroke (stop approx. 100 mm (3.9 in) before the end of stroke).
NOTICE
If the engine is run immediately at high speed or the cylinder is operated to the end of its stroke, the air inside the cylinder will
cause damage to the piston packing.
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MAINTENANCE MAINTENANCE