TM 9-4120-407-14
4-18. CHARGING THE REFRIGERANT SYSTEM. (Cont)
(10) With the Air Conditioner running, observe sight glass on back of condenser section. Be sure that
the compressor is running.
(a ) Green center means refrigerant moisture content is acceptable.
(b) Yellow center means there is too much moisture in system. It must be discharged, evacuated,
and charged again.
(c) Milky white or bubbly liquid means system has low charge.
Figure 4-11. Refrigerant Charging (Partial Systems/Small Quantify Charge)
(d) Clean bubble-free liquid around center means the system is fully charged.
Never introduce liquid refrigerant into the low pressure (suction)
charging valve. This can cause damage to the compressor.
(11) If charge is low, carefully add refrigerant.
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