Venting And Priming Hydraulic System - Doosan DX700LC Operation And Maintenance Manual

VENTING AND PRIMING
HYDRAULIC SYSTEM
Main System Pump
NOTE:
If pump is run without sufficient oil in the main
hydraulic pump, damage can occur. Always vent
pump of air after draining hydraulic system.
1. Shut down engine.
2. Remove flushing hose (1) from the adapter (2).
3. Remove adapter (2) and O-ring from the pump housing.
4. Fill pump housing with hydraulic oil.
5. Install new O-ring onto adapter (2) and assemble the
adapter on pump housing.
6. Connect flushing hose (1) to adapter (2).
7. Start engine, and run at "LOW IDLE". Raise boom to its
maximum height.
8. Very slowly loosen negative control hose connector (3)
until hydraulic oil start to leak from the connection.
9. When hydraulic oil begins to leak, tighten hose connector.
10. Shut down engine, turn starter switch "ON", and slowly
lower the boom until the bucket pin touches the ground.
(This will increase the air pressure in the hydraulic tank)
11. Slowly loosen air bleeding plug (4) until hydraulic oil leaks
out.
12. When hydraulic oil begins to leak, then tighten plug (4).
Hydraulic Cylinders
IMPORTANT
If cylinders are operated in high idle after the hydraulic
system has been drained or the cylinder has been rebuilt,
damage to piston packing and seals may occur. Always
vent air from cylinders at low idle and at a slow speed.
1. Run engine at low idle. Extend and retract each cylinder to
within 100 mm (4 in) of fully stroking it 4 - 5 times.
2. Operate fully extend and retract each cylinder 3- 4 times.
3. Repeat procedure until cylinders extend and retract
smoothly.
Inspection, Maintenance and Adjustment
2
Figure 155
1
2
1
FG016141
OP001123
4-89