Sakai SV400D-2, Руководство по ремонту

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9-044
HYDRAULIC SYSTEM TROUBLESHOOTING
3-3-2. Vibrator frequency is too low
Check point Cause Check/Action
1. Oil Level of Hydraulic Oil
Tank
Oil level in hydraulic oil tank is low. Fill the tank until the correct oil level is
obtained.
2. Charge Pressure The stroke of the vibrator pump
swash plate is small because the
charge pressure is low, decreasing the
discharge rate of the vibrator pump. Measure the charge pressure. If low,
check the propulsion or vibrator charge
relief valve, and then adjust or replace
the valve.
Insufficient charge pump discharge
Repair or replace charge pump.
Charge pressure decreases due to
internal leakage of solenoid valve
connecting oil supply circuit with charge
circuit.
- Parking Brake solenoid valve
- Speed change solenoid valve When the solenoid is not energized,
check if oil flows in return circuit to
tank. If oil flows, carry out the following
actions.
- Repair or replace the solenoid valve.
- Repair or replace the solenoid valve.
3. Vibrator Motor Inlet
Pressure
Vibrator motor inlet pressure is low. Measure the vibrator motor inlet
pressure. If low, check the relief valve,
and then adjust or replace the valve.
4. Internal Leakage of
Vibrator Motor
Vibrator motor revolutions decrease due
to internal leakage of the vibrator motor. Measure the drain quantity from vibrator
motor. If the drain quantity is larger than
the standard value, repair or replace the
motor.
5. Pressure Setting in
Vibrator Circuit Relief
Valve
Low circuit pressure due to incorrect
relief setting. If the reverse phenomenon occurs when
the relief valves in the high/low vibrator
circuits are exchanged with each other,
check the relief valves, then adjust or
replace the valves.
6. Vibrator Pump The pump discharge rate decreases
due to efficiency degradation of vibrator
pump.
Use a flow meter to measure the
amount of vibrator pump discharge. If it
is lower than the standard flow amount,
repair or replace the vibrator pump.
3-3-3. Vibrator L-H does not switch
Check point Cause Check/Action
1. Vibrator Solenoid Valve The vibrator solenoid valve spool
changes only to one side. Repair or replace the vibrator solenoid
valve.
3-3-4. Vibrator does not stop
Check point Cause Check/Action
1. Vibrator Solenoid Valve Spool of vibrator solenoid valve does
not return to neutral position. Repair or replace the vibrator solenoid
valve if the spool of the valve does not
return to neutral position.
2. Vibrator Pump The vibrator pump swash plate does not
return to the neutral position. Repair or replace the vibrator pump.