Komatsu D31EX-21, Руководство по эксплуатации и техническому обслуживанию, Страница: 214 / 256

SERVICE PROCEDURE
MAINTENANCE
4-34
PROCEDURE FOR BLEEDING AIR IN HYDRAULIC SYSTEM 4
When the hydraulic oil filter elements or strainers are cleaned or replace, or when any hydraulic component has
been repaired or replaced, or when a hydraulic piping has been disconnected, bleed air from the hydraulic oil cir-
cuit.
See “STARTING ENGINE (3-77)“.
Since the engine must be started and the blade must be operated, see OPERATION.
1. Bleeding air from pump
2. Loosen air bleed plug (1) installed to the drain port and
check that oil oozes out (air bleeding is completed).
3. After completion of the air bleeding operation, tighten the
air bleed plug.
NOTICE
If the pump is run when the pump case is not full of oil,
there will be abnormal generation of heat, and this will lead
to premature failure of the pump.
4. Starting engine
Start the engine and run for 10 minutes at low idling. For details, see “STARTING ENGINE (3-77)“.
After running for 10 minutes at low idling, move to the next operation.
5. Bleeding air from cylinders
6. Run the engine at low idling, and extend and retract each
cylinder 4 to 5 times, taking care so that a cylinder may not
be brought up to its stroke end. (Stop the cylinder approx.
100 mm short of its stroke end)
7. Next, operate each cylinder 3 to 4 times to the end of its
stroke.
8. Finally, operate each cylinder 4 to 5 times to the end of its
stroke to completely remove the air.
NOTICE
If the engine is run at high speed immediately after startup or a cylinder is pushed up to its stroke end, air
taken inside the cylinder may cause damage to the piston packing.
9. Operation
10. After completing the bleeding of the air, stop the engine,
and wait for at least 5 minutes before starting operations.
This will release the bubbles in the oil inside the tank.
11. Check that there is no oil leakage, and wipe off any oil that
has been spilled.