Sakai CR271, Руководство по ремонту

Страница: 166 / 170

10-023
TROUBLESHOOTING
3-2-2. Machine moves in one direction only (forward or backward)
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. High Pressure
Relief Valve
Low circuit pressure due to incorrect high
pressure relief setting or internal leakage of
high pressure valve.
• Interchange two multifunction valves.
• If faulty condition is accordingly reversed,
inspect high pressure relief valve or
replace it if necessary.
3-2-3. Slow machine speed or small drive force
Check point Cause Check/Action
1. Bypass Valve Bypass valve is slightly open. Close bypass valve completely.
2. F-R Lever Linkage F-R lever linkage is faulty. Check and adjust F-R lever linkage or
replace it if necessary.
3. Charge Circuit
Pressure
Stroke of propulsion pump swash plate
is small because charge pressure is low,
decreasing discharge rate of propulsion
pump.
• Measure charge pressure.
• If low, inspect charge relief valve or
replace it if necessary.
Insufficient charge pump discharge. Repair charge pump or replace it if
necessary.
4. Suction Filter for
Charge Pump
Flow rate of charge pump decreases as
well as charge pressure decreases due to
clogged filter.
Clean suction filter or replace it if necessary.
5. Propulsion Motor Propulsion motor inlet pressure is low. • Measure propulsion motor inlet pressure.
• If low, inspect high pressure relief valve or
replace it if necessary.
Propulsion circuit pressure is not held in
propulsion motor case.
If pressure in propulsion motor case is not
within allowable range, 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.
If pressure in propulsion pump case is not
within allowable range, repair propulsion
pump or replace it if necessary.