EP Equipment CQD16, Service Manual

Page: 94 / 251

80
REV. 07/2016
HYDRAULIC SYSTEM
7
7.4.3 Faults and Causes
1
Fault
The vehicle cannot perform the
hydraulic control instructions
Cause
a. Solenoid valve failure;
b. Insuf
fi cient power supply
voltage;
c. Valve seat blocked by large
impurities;
d. External leakage: sealing
damaged;
poor threaded connection;
valve body defects;
e. High viscosity of hydraulic oil;
f. High frequency of use, service
life has expired already.
2
Fault Slow pace of actuator
Cause
a. Over fl ow valve in the connection
block started;
b. Valve seat leakage;
c. Solenoid valve failure;
d. High viscosity of hydraulic oil;
e. High frequency of use, service
life has expired already.
Checking
-
-
Check the valve seat for leakage and dama-
ge;
Check the solenoid valve connector for
loosening or poor connection of leads.
7.4.4 Checking and Testing
Testing
-
- Switch off the power supply of the vehicle;
Measure the resistance between solenoid
valve coil end point A and B to identify if the
coil is normal. (See Section 7.5.2)
7.4.5 Control Circuit Troubleshooting
Solenoid Valve Control Circuit
(Figure 90409)
Check if the circuit is broken by using a multi-
meter:
-
- Set the multimeter to ON-OFF;
Check if the circuit between solenoid valve
and controller is conducted.
Lifting
Solenoid Valve
Lowering
Solenoid Valve
Reach
Solenoid Valve
Right Shifting
Solenoid Valve
Left Shifting
Solenoid Valve
Retracting
Solenoid Valve
Forward Tilting
Solenoid Valve
Backward Tilting
Solenoid Valve