TM 5-3805-291-23-1
AIR CONDITIONING SYSTEM TESTS, INSPECTIONS, AND ADJUSTMENTS - CONTINUED
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REFRIGERANT LEAKAGE TEST
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N OT E
Finding leaks and repairing leaks from refrigerantis important since AC is a closed circuit sys-
tem.
System must contain at least 0.88 lb (0.4 kg) ofrefrigerant to perform leak test. Install manifold
gage set to determine if pressure exists in system. Manifold gage set can determine if pressure
exists in system. A leak test can be performed if system indicates pressure.
Refrigerant vapor is heavier than air. For bestresults, place black light directly below possible
leaks.
Leaks in high pressure side of system are more easily found if AC is ope ated for 5 to 10 minutes.
r
Leak test must be performed immediately after unit is turned OFF. Leak test for high pressure
side is performed before pressures in system equalize. Leaks in low pressure side of system are
more easily found if AC has been turned OFF for 5 to 10 minutes. Leak test for low pressure side
is performed after pressures in system equalize.
Under normal conditions, R-134a AC systems thathave P80 hoses may lose as much as 0.0400 lb
(0.018 kg) of refrigerant per foot of hose per year.
Refrigerants which are not approve may have higher leakage rates.
d
Dye
1.
Move leak detection lamp along possible leak points. When a leak is present, lamp will illuminate dye in refrigerant.
2.
If a leak is found in AC system, use a Refrigerant Leak Detector in order to confirm leak was detected by use of leak
detection lamp.