WD Catalog 2018

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Chapter 8 – Troubleshooting & Service Procedures
8-12 - -
After finding a leak, recover all refrigerant from
the system and repair the leak. Check the com-
pressor and replace any refrigeration oil lost due
to leakage. Evacuate and recharge the system
with refrigerant, then check AC operation and
performance.
0
100
200 300
400
500
HIGH
TEMPERATURE
LOW
TEMPERATURE
150
120
90
60
30
0
10
20
30
Air and/or Moisture in the System
LOW SIDE NORMAL HIGH SIDE NORMAL
Tip: The sight glass may be clear or show some bubbles.
The air from vents in the cab is only slightly cool.
In a cycling clutch type system with a thermostatic
switch, the switch may not cycle the clutch on and
off, so the low pressure gauge will not fluctuate.
Cause: Air and/or moisture in the system.
RepairProcedure:
Test for leaks, especially around the compressor
shaft seal area. When the leak is found, recover
refrigerant from the system and repair the leak.
Replace the receiver-drier or accumulator because
the desiccant may be saturated with moisture
(there is no way to tell). Check the compressor and
replace any refrigeration oil lost due to leakage.
Evacuate and recharge the system with refriger-
ant, then check AC operation and performance.
Figure 8-7
Gauge reading, air and/or
moisture in the system.