EP Equipment CQD16, Service Manual

Page: 183 / 251

REV. 07/2016
TROUBLESHOOTING
9
169
Table 9.1 Troubleshooting of Common Faults (continued)
Fault Fault Symptom Troubleshooting Order * Troubleshooting Measures
Hydraulic
Failure 1. The vehicle cannot
lift 1. Pump motor does not work:
a. Foot switch and seat switch or
its circuit connection failure
b. Pump motor or its circuit
connection failure
c. Control switch or its circuit
connection failure
d. Controller failure
2. Pump motor works:
a. Overload
b. Insuf
fi cient hydraulic oil
c. Hydraulic pipeline leakage
d. Pump motor reverse rotation
e. Cylinder failure (blocked)
f. Solenoid valve blocked and
cannot reset
g. Valve body failure:
excessive wear of gear pump,
serious internal leaks, insuf
fi cient
pressure of relief valve or
blocked, check valve blocked
1. Pump motor does not work:
1) Check if the foot switch and
seat switch or the connection of
its circuit is normal (see Section
8.7 and Section 8.11);
2) Check the pump motor and its
connection circuit;
(see Section 7.3)
3) Check the control button and its
connection circuit;
(see Section 6.4 or 6.5)
4) Replace the controller.
2. Pump motor works:
1) Refer to the rated capacity
marked on the nameplate;
2) Lower the mast to the bottom,
check if the amount of oil in the
oil tank can meet the requireme-
nts (see Section 2.2.3);
3) Check the pipe and hydraulic
components for oil leaks;
4) Check the pump motor wiring;
5) Check the cylinder for damage
or deformation, remove the
cylinder to check for wear or
aged seals inside;
(see Section 7.9)
6) Wash or replace the solenoid
spool (see Section 7.5)
7) Wash or replace the valve body
(see Section 7.4 or 7.6)
2. The vehicle cannot
be lowered a. Solenoid valve (or manual
valve) or its circuit connection
failure
b. Lowering switch or its circuit
connection failure
c. Valve failure;
d. Cylinder deformation or blocked
e. Explosion-proof valve blocked 1) Check the lowering button and
its connection circuit;
(see Section 6.4 or 6.5)
2) Check the solenoid valve and
its connection circuit;
(see Section 7.5)
3) Check the cylinder for
deformation, remove the
cylinder to check if the internal
assembly is normal
(see Section 7.9)
4) Clean or replace the valve;
(see Section 7.4 or 7.6);
5) Replace the explosion-proof
valve (see Appendix A)
* Carry out trouble shooting in accordance with the order listed
in the table, it can help you quickly identify problems and
resolve accordingly.