Komatsu PC138US-11 Operation & Maintenance Manual page 354

MAINTENANCE PROCEDURE
NOTICE
If the engine runs at high speed immediately after startup or a cylinder is pushed up to its stroke end,
air mixed into the cylinder may cause damage to the piston packing or etc.
1.
Run the engine and keep it at low idle speed.
2.
Extend and retract each cylinder 4 to 5 times, taking care that a cylinder is not moved to the stroke end.
(Stop the cylinder approximately 100 mm short of its stroke end.)
3.
Operate each cylinder 4 to 5 times to each stroke end.
All air is bled.
METHOD FOR BLEEDING AIR FROM SWING MOTOR
Perform it only when the oil inside the swing motor case is drained.
NOTICE
If the air is not bled from the swing motor, the motor bearings may be damaged.
1.
Run the engine at low idle.
2.
Remove the cover (2).
3.
Loosen the hose at motor S port (3), and check that oil
oozes out from the fitting of the motor S port (3).
NOTICE
At this time, do not swing the upper structure.
4.
If oil does not ooze out, stop the engine, remove the motor
S port (3), and fill the motor case with hydraulic oil.
5.
After completely bleeding the air, tighten the motor S port
(3).
6.
Run the engine at low idle and slowly swing at least 2
turns uniformly to the right and left.
METHOD FOR BLEEDING AIR FROM TRAVEL MOTOR
Bleed air only when the oil in the swing motor case is drained.
1.
Run the engine at low idle.
2.
Loosen the hose (4) of port C. When oil flows out, tighten
it.
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MAINTENANCE