Manifold Gauge Set Readings
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
The sight glass is clear or shows oil streaks. The
air from vents in the cab seems warm. If there is a
low pressure or Trinary switch in the system it
Extremely low or no refrigerant in the system.
There is a leak in the system.
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
It may be necessary to use a jumper wire to
bypass some types of low pressure cutout
when you add refrigerant to the system.