WD Catalog 2018

913 / 1003

8-13 - -
0
100
200 300
400
500
HIGH
TEMPERATURE
LOW
TEMPERATURE
150
120
90
60
30
0
10
20
30
Excessive Air and/or Moisture in the System
LOW SIDE HIGH HIGH SIDE HIGH
Tip: There may be occasional bubbles in the sight glass.
Air from vents in the cab is only slightly cool.
Cause: System contains excessive air and/or moisture.
Repair Procedure:
Test for leaks, recover refrigerant from the sys-
tem and repair the leak. Depending on the type
of system, replace the receiver-drier or accumu-
lator. The desiccant is saturated with moisture.
Check and replace any compressor oil lost due to
leakage. Evacuate and recharge the system,
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
Expansion Valve (TXV) Stuck Closed or Plugged
LOW SIDE LOW OR VACUUM HIGH SIDE HIGH
Tip: Air from vents in the cab is only slightly cool.
The expansion valve body is frosted or sweating.
Manifold Gauge Set Readings
Figure 8-8
Gauge reading, excessive air
and/or moisture in the
system.
Figure 8-9
Gauge reading, expansion
valve (TXV) stuck closed.