EP Equipment CQD16, Service Manual

Page: 90 / 251

76
REV. 07/2016
HYDRAULIC SYSTEM
7
7.2 Hydraulic Power Unit
7.2.1 Removal and Installation
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Open the engine hood;
Remove the AMP connector on the pump
motor and pump motor and carry out the fol-
lowing operations to the motor(1) remove the
three cables U, V and W connected to the
controller;
Remove the tubing head between gear pump
(2) and multi-way valve with a wrench, and
then remove the tubing (3);
Loosen the clamp (5) on inlet tubing (4);
Loosen the four pump motor mounting bolts
(6) and remove the pump motor (1);
Loosen the two gear motor mounting bolts (7)
and remove the gear motor (2).
Removal
Installation
- Install according to the reverse order of rem-
oval.
When removing the tubing and gear pump, the
system will lose some hydraulic oil, please refer
to Section 2.2.3 for supplementary adding of
hydraulic oil.
CAUTION
7.3.2 Faults and Causes
1
Fault Motor does not rotate
Cause
a. Cable U, V, or W is broken;
b. Loosening connections to cable
U, V or W ;
c. Stator coil open circuit;
d. Motor bearing damage;
e. Speed encoder or its circuit
failure.
2
Fault
Motor is rotating in slow speed and
reverse
Cause Cable connection error
3
Fault
Motor with abnormal noise or
vibration
Cause
a. Uneven clearance between
stator and rotor;
b. Bearing failures;
c. Loosening
fi xing screws on
motor housing.
4
Fault Motor smoking or burning smell
Cause
Stator winding short circuit, motor
burnt
7.3 Pump Motor
This truck obtains hydraulic power through the
AC pump motor.
Temperature
Sensor
Speed Encoder
7.3.1 Removal and Installation
See Section 7.2.1 .