5-55
MAINTENANCE
10. Remove the relay and fuse panel (9).
11.Loosentheboltsandremovetheange
(7).
12. Remove the suction strainer (8) and
clean it.
13. Clean the inside of the hydraulic tank.
14. Remove the connector (C) and install the
cap (B).
15. Install the suction strainer (8) on the tank
and then install the flange (7).
16. Install the new return filter (5) and the
flange (4) on the tank.
17. Add hydraulic oil from the hole of plug (3)
up to the level between the upper limit
(H)andthelowerlimit(L)inthesight
gauge (1).
18. Tighten the plug (3).
19. Install the relay and fuse panel (9).
20. Bleed air from the hydraulic oil circuit
following “Bleeding air” below.
21. Set the machine to the hydraulic oil level
inspection posture and inspect the oil
level after the oil cools.
Refer to “Inspect the hydraulic oil tank
level and replenishing” on page 5-20.
Bleeding air
IMPORTANT: After replacing the hydraulic
oil, bleed air from the hydraulic circuits
and hydraulic devices. Failure to do so
may damage the hydraulic devices.
•Hydraulicpump
EVERY 4000 HOURS
1. Open the engine hood.
2.Loosenthedrainhose(1)ofthehydraulic
pump.
3.
Tighten the drain hose (1) once there are
no more air bubbles coming from the
elbow(2)joint.
•Slewmotor
1.Loosentheair-bleedingplug(1).
2. Tighten the plug (1) once the hydraulic oil
overflows from the air-bleeding plug hole
(1).
•Cylinders
1. Start the engine, let it run at a low-idling
speed for 10 minutes.
2. Maintain the engine at low idle, and then
slowly extend and retract each cylinder 4
or 5 times, without letting them reach the
stroke end.
3. While running the engine at high speed,
slowly extend and retract each cylinder 4
or 5 times, without letting them reach the
stroke end.
4. Return the engine speed to low idle, and
then slowly extend and retract each
cylinder 4 or 5 times to the stroke end.