WEICHAI WD10 Service Manual - page 142
Service Manual for WD10 Diesel Engine
132
4
The belt is too tight, which leads to
vibration of A/C compressor
Adjust the belt tension, it is suitable if the belt is
depressed 10~14mm after loading 10kg force.
5
Misalignment of pulley shafts, or the
belt is not on the same plane, which
leads to vibration of A/C compressor
Reassemble the compressor to keep the shafts
aligned and belt on the same plane.
6
Loose compressor fastening bolts;
loose or damaged support
Tighten the bolts; replace compressor support.
7
Compressor internal part is damaged Replace the compressor.
8
Excessive coolant leads to vibration
of high pressure pipe, and compressor
produces knocking noise
Drain out the coolant until high pressure gauge
indicates normal.
(2) A/C compressor doesn’t work after A/C is turned on
Possible causes and maintenance methods for A/C compressor working failure are listed in Table
4-3.
Table 4-3 Troubleshooting for A/C compressor working failure
Problem: A/C compressor doesn’t work
S/N
Possible cause
Maintenance method
1
A/C switch failure
Check, repair or replace the switch.
2
Clutch coil failure or loose connector Tighten the connector, replace the clutch.
3
Low voltage or clutch coil burnout
due to short circuit, which leads to
clutch fail to pull-in or slipping
Find out the cause for low voltage, increase the
voltage or check the circuit, replace the
compressor if there is short circuit.
4
Loose or breakage of belt
Adjust or replace the belt.
5
High-low pressure switch failure or
open circuit
Check the switch, find out what caused the open
circuit, and replace if necessary.
6
Excessive clutch air clearance
Replace the compressor.
7
Clutch pulley doesn’t rotate
Replace the compressor.
8
Compressor internal part is damaged Replace the compressor.
(3) Precautions for maintenance of A/C compressor
1) After disassembling of A/C system, all parts should be sealed in time. Removed parts of A/C
system cannot be exposed to air for long time, in order to prevent moisture in the air infiltrating
into A/C compressor system.