Sakai SV400D-2, Shop Manual

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9-043
HYDRAULIC SYSTEM TROUBLESHOOTING
3-3. Vibrator
If a problem occurs in the vibrator system such as vibrator pump, vibrator motor, or vibrator solenoid
valve, determine the cause and carry out action as required, according to the following general
troubleshooting items.
When checking whether or not the pressure is correct, refer to the pressure standard value for
each hydraulic circuit.
3-3-1. No vibration
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. Pressure in Vibrator
Circuit
The circuit does not obtain the required
pressure because the pressure setting
of relief valve is low. Measure the vibrator circuit pressure.
If low, check the relief valve, and then
adjust or replace as required.
3. Charge Circuit Pressure Vibrator pump does not discharge oil
because charge pressure is low. 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.
4. Vibrator Solenoid Valve Vibrator pump does not discharge
oil because the spool of the vibrator
solenoid valve does not shift. Repair or replace the vibrator solenoid
valve.
5. Vibrator Pump
The pump discharge rate is insufficient
due to efficiency degradation of vibrator
pump.
Measure the discharge flow rate of
vibrator pump with flow meter. If the
discharge flow rate is not within the
specified range, repair or replace the
vibrator pump.
The pump is not discharging oil due to
wear of the vibrator pump drive shaft
spline. Replace the vibrator pump.
6. Vibrator Motor Internal leakage of vibrator motor. Measure the drain quantity from vibrator
motor. If the drain quantity is larger than
the standard value, repair or replace the
motor.
Output torque is not transmitted due
to worn spline of vibrator motor output
shaft. Replace the vibrator motor.
7. Power Transmission
Coupling
Rotation is not transmitted due to worn
spline of power transmission coupling. Replace the power transmission
coupling.