Manifold Gauge Set Readings
Excessive Air and/or Moisture in the System
Gauge reading, excessive air
and/or moisture in the sys-
There may be occasional bubbles in the sight glass.
Air from vents in the cab is only slightly cool.
System contains excessive air and/or moisture.
Test for leaks, recover refrigerant from the system
and repair the leak. Depending on the type of
system, replace the receiver-drier or accumulator.
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.
Expansion Valve (TXV) Stuck Closed or Plugged
Gauge reading, expansion
valve (TXV) stuck closed.
Air from vents in the cab is only slightly cool. The
expansion valve body is frosted or sweating.