Sakai SW880-1, Shop Manual

Page: 423 / 428

11-213
TROUBLESHOOTING
3-3-4. Amplitude does not switch between high and low
Check point Cause Check/Action
1. Vibrator Pump
Proportional
Solenoid Valve
Only high or low side proportional pressure
reducing valve works.
Repair vibrator pump proportional solenoid
valve or replace them if necessary.
2. Servo Control
Valve
Servo control valve spool shifts only in one
direction.
Repair servo control valve spool or replace
it if necessary.
3-3-5. Vibrator does not stop
Check point Cause Check/Action
1. Servo Control
Valve
Servo control valve spool does not return to
neutral position.
Measure vibrator high/low circuit pressure.
If not equal, check and adjust servo control
valve or replace it if necessary.
•
•
2. Vibrator Pump Vibrator pump swash place does not return
to neutral position.
Repair vibrator pump or replace it if
necessary.
3-3-6. Vibrator 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 vibrator closed circuit is
insufficiently cooled due to flushing valve
shuttle spool sticking.
Repair flushing valve or replace it if
necessary.
Hydraulic oil in vibrator 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 vibrator closed circuit is
insufficiently cooled due to flushing valve
relief valve poppet sticking.
Clean flushing relief valve or replace it if
necessary.
4. Vibrator Circuit
Pressure
If circuit pressure setting is excessively low,
relief valve opens, causing temperature of
hydraulic oil in circuit to rise.
Measure vibrator circuit pressure.
If low, check and clean relief valve or
replace it if necessary.
•
•
If load is excessively heavy, relief valve
opens, causing temperature of hydraulic oil
in circuit to rise.
Measure vibrator circuit pressure.
If high, decrease vibration load.
•
•
5. Suction Filter for
Vibrator Charge
Pump
Load of vibrator 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 2 Charge circuit pressure increases due to
clogged filter.
Clean hydraulic oil filter 2 or replace it if
necessary.