Swing System - Doosan DX700LC Operation And Maintenance Manual

Problem
All actuators have low
power.
Only one or two actions
have little or no power.
Oil temperature too high.

SWING SYSTEM

Problem
No swinging motion.
Swing motion jerky.
Troubleshooting
6-4
Cause
Low hydraulic oil level.
Suction filter clogged.
Hydraulic pumps faulty.
Main relief pressure too low.
Hydraulic pumps excavating.
Overload relief pressure too low.
Makeup check valve leaking.
Control valve spool faulty.
Dirt in valve spool.
Actuator failed.
Cylinder seal failed.
Cylinder rod damaged.
Remote control valve failed.
Wrong pilot line connection.
Oil cooler faulty.
Fan belt loose.
Cause
Swing brake valve faulty.
Hydraulic timer faulty.
Low brake release pressure.
Swing motor failed.
Remote control valve failed.
Wrong pilot line connection.
Swing gear worn.
Swing bearing damaged.
Improper lubrication.
Remedy
Add hydraulic oil as required.
Clean filter.
Contact your DOOSAN dealer.
Contact your DOOSAN dealer.
Bleed air from hydraulic pumps.
Reset pressure.
Clean or replace as required.
Replace valve spool.
Clean or replace as required.
Repair or replace as required.
Repair or replace as required.
Repair or replace as required.
Replace control valve.
Reconnect pilot lines.
Contact your DOOSAN dealer.
Tighten fan belting as required.
Remedy
Replace brake valve.
Replace timer.
Adjust pressures.
Replace swing motor.
Replace control valve.
Reconnect pilot lines.
Replace swing gear.
Replace bearing.
Add grease.
OP000030