Sakai SW880-1, Shop Manual

Page: 420 / 428

11-210
TROUBLESHOOTING
3-2-5. Propulsion system is overheating
Check point Cause Check/Action
1. Oil Level of
Hydraulic Oil Tank
Oil level in hydraulic oil tank is low. Fill tank until correct oil level is obtained.
2. Oil Cooler Cooling efficiency is reduced due to clogged
oil cooler fins.
Clean oil cooler fins.
3. Flushing Valve Hydraulic oil in propulsion closed circuit is
insufficiently cooled due to flushing valve
shuttle spool sticking.
Repair flushing valve or replace it if
necessary.
Hydraulic oil in propulsion closed circuit is
insufficiently cooled because flushing valve
relief setting pressure is excessively high.
Check dust or damage in flushing relief
valve and replace it if necessary.
Hydraulic oil in propulsion closed circuit is
insufficiently cooled due to flushing valve
relief valve poppet sticking.
Clean flushing relief valve or replace it if
necessary.
4. Propulsion Circuit
Pressure
If circuit pressure setting is excessively low,
relief valve opens, causing temperature of
hydraulic oil in circuit to rise.
Measure propulsion circuit pressure.
If low, increase relief setting pressure.
•
•
If load is excessively heavy, relief valve
opens, causing temperature of hydraulic oil
in circuit to rise.
Measure propulsion circuit pressure.
If high, decrease propulsion load.
•
•
5. Suction Filter for
Steering • Charge
Pump
Load of steering • charge pump increases
due to clogged filter, causing temperature of
hydraulic oil in circuit to rise.
Clean suction filter or replace it if necessary.
6. Hydraulic Oil Filter 1 Charge circuit pressure increases due to
clogged filter.
Clean hydraulic oil filter 1 or replace it if
necessary.
3-2-6. Abnormal noise from propulsion system
Check point Cause Check/Action
1. Axle Bearings Axle bearings supporting front and rear
drums are damaged.
Replace axle bearings.
2. Hydraulic Hose
Clamp
Vibrator sound of hydraulic hose is
generated because clamp securing
hydraulic hose is loose.
Tighten bolts of loose hydraulic hose clamp
to specified torque.
3. Suction Filter for
Steering • Charge
Pump
Cavitation is occurring in steering • charge
pump due to clogged filter.
Clean suction filter or replace it if necessary.
4. Charge Circuit
Pressure
If charge pressure is low, brake cannot be
released completely, which causes brake
drag.
Measure charge pressure.
If low, check and adjust charge relief valve
or replace it if necessary.
•
•
5. Propulsion Motor Internal bearing of propulsion motor is
damaged.
Repair propulsion motor or replace it if
necessary.