EP Equipment CQD16, Service Manual

Page: 184 / 251

REV. 07/2016
TROUBLESHOOTING
9
170
Table 9.1 Troubleshooting of Common Faults (continued)
Fault Fault Symptom Troubleshooting Order * Troubleshooting Measures
Lift Failure 3. Slow Lifting of
Vehicle a. Overload
b. Hydraulic pipeline leakage
c. Valve failure:
Gear pump wear, internal
leakage occurs
Insuf
fi cient relief valve pressure
or blocked
1) Refer to the rated capacity
marked on the nameplate;
2) Check the pipe and hydraulic
components for oil leaks;
3) Wash or replace the valve body
(see Section 7.4 or 7.6)
4. Slow Lowering of
Vehicle a. Solenoid valve blocking
b. Valve body failure: throttle valve
failure or blocked 1) Wash or replace the solenoid
spool (see Section 7.5)
2) Wash or replace the valve body
(see Section 7.4 or 7.6)
5. Unstable Lifting /
Lowering of Vehicle a. Chain loosening;
b. Poor lubrication between steel
channel and rollers;
c. Improper adjustment of rollers,
or blocked;
d. Accumulator failure; 1) Adjust the chain tension;
(see Appendix A1-1.1)
2) Check if the steel channel
grease is normal, clean and re-
lubricate steel channel and
rollers;
3) Adjust the side roller spacing
through roller screw; or replace
the roller;
4) Replace the accumulator.
* Under the circumstances of normal lifting and lowering, if failure occurs to any of other
hydraulic actions (forward/backward shifting, forward/backward tilting and left/right shifting),
perform troubleshooting to the corresponding control switch and its control circuit.
Steering Fault 1. The vehicle cannot
be steered (the
vehicle can travel)
a. Stepper motor or its circuit
connection failure
b. Steering motor or its circuit
connection failure
c. Proximity switch or its circuit
connection failure
d. Steering controller failure Controller failure error, carry out
troubleshooting according to the
fault code information on the
instrument (see Section 8.14).
1) Check if the mechanical
connection between the
steering wheel and stepper
motor is solid;
(see Section 6.1)
2) Check the stepper motor or its
connection circuit;
(see Section 6.6)
3) Check the steering motor or its
connection circuit;
(see Section 5.6)
4) Check the proximity switch or
its connection circuit.
(see Section 5.5)
5) Replace the controller.
* Carry out trouble shooting in accordance with the order listed
in the table, it can help you quickly identify problems and
resolve accordingly.