Sakai SW354, Shop Manual

Page: 425 / 480

10-076
TROUBLESHOOTING
3-2-3. Slow machine speed or small drive force 2/2
Check point Cause Check/Action
5. Propulsion Motor Propulsion motor inlet pressure is low. Measure propulsion motor inlet pressure.
If low, check and adjust high pressure
relief valve or replace it if necessary.
•
•
Propulsion circuit pressure is not held in
propulsion motor case.
Measure propulsion motor case pressure.
If case pressure is not within allowable
pressure, repair propulsion motor or
replace it if necessary.
•
•
Output of propulsion motor decreases and
number of revolutions decreases due to
internal leakage of propulsion motor.
Measure drain quantity from propulsion
motor.
If drain quantity is larger than standard
value, repair propulsion motor or replace it
if necessary.
•
•
6. Propulsion Pump Discharge flow rate is insufficient due to
efficiency degradation of propulsion pump.
Measure discharge flow rate of propulsion
pump with flow meter.
If discharge flow rate is not within specified
range, repair propulsion pump or replace it
if necessary.
•
•
Discharge flow rate is insufficient due to
wear of propulsion pump drive shaft splines.
Replace propulsion pump.
Propulsion circuit pressure is not held in
propulsion pump case.
Measure propulsion pump case pressure.
If case pressure is not within allowable
pressure, repair propulsion pump or
replace it if necessary.
•
•
3-2-4. Machine speed cannot be switched
Check point Cause Check/Action
1. Charge Circuit
Pressure
Insufficient steering • charge pump
discharge.
Repair steering • charge pump or replace it
if necessary.
Charge pressure decreases due to internal
leakage of solenoid valve connecting oil
supply circuit with charge circuit.
Speed change solenoid valve
Parking brake solenoid valve
•
•
When solenoid is energized, check if oil
flows in return circuit to tank.
If oil is flowing, repair solenoid valve or
replace it if necessary.
•
•
2. Speed Change
Solenoid Valve
Machine speed does not change because
spool of speed change solenoid valve does
not change.
Repair speed change solenoid valve or
replace it if necessary.
3. Propulsion Motor
Speed Change
Spool
Propulsion motor speed change spool is
faulty.
Replace speed change spool.
3-2-5. Machine does not stop completely with F-R lever in “N”
Check point Cause Check/Action
1. F-R lever Linkage F-R lever linkage is faulty. Check and adjust F-R lever linkage or
replace it if necessary.
2. Propulsion Pump
Servo Cylinder
Faulty propulsion pump servo cylinder or
faulty pump swash plate setting.
Repair propulsion pump or replace it if
necessary.