Manifold Gauge Set Readings
Repair Procedure:
Check for leaks with your leak detector. If you find
a leak at a connection, tighten it then add refriger-
ant as necessary. If a component or line is leaking
(defective), recover all refrigerant from the system.
Replace the defective part and then check the com-
pressor oil level and replace missing oil. Evacuate
and recharge with refrigerant, then check AC op-
eration and performance.
Extremely Low Refrigerant Charge in the System
Gauge reading, extremely
low refrigerant charge in
system.
The sight glass is clear or shows oil streaks. The
Tip:
air from vents in the cab seems warm. If there is a
TM
low pressure or Trinary switch in the system it
may have shut off the compressor (clutch).
Extremely low or no refrigerant in the system.
Cause:
There is a leak in the system.
Repair Procedure:
Add refrigerant to the system, at least half of the
normal full charge amount. Then perform your
leak test. As an alternative to a refrigerant, add
dry nitrogen gas to the system and then test for
leaks.
It may be necessary to use a jumper wire to
Note:
bypass some types of low pressure cutout
switches to operate the compressor (clutch)
when you add refrigerant to the system.
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