TM 5-3805-290-23-1
AIR CONDITIONING SYSTEM TESTS, INSPECTIONS, AND ADJUSTMENTS - CONTINUED
0018 00
REFRIGERANT LEAKAGE TEST
0018 00
Dye
N OT E
Finding leaks and repairing leaks from refrigerant is important since AC is a closed circuit system.
System must contain at least 0.88 lb (0.4 kg) of refrigerant to perform leak test. Install manifold gage set to
determine if pressure exists in system. A leak test can be performed if system indicates pressure.
Refrigerant vapor is heavier than air. For best results, place black light directly below possible leaks.
Leaks in high pressure side of system are more easily found if AC is operated for 5 to 10 minutes. 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.
1.
Move black light along possible leak points. When a leak is present, black light 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 black
light.
Leak Detector
N OT E
Refrigerant Leak Detectors are designed to detect leaks as small as 0.25 oz (7.4 ml) per year of refrigerant
in air conditioning system. Perform the following procedure in order to determine if system has a leak.
Refrigerant vapor is heavier than air. For best results, place sensor tip directly below possible leaks.
Under normal conditions, R-134a AC systems that have 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 approved may have higher leakage rates.
1.
Move sensor tip along possible leak points at a rate of 1 in. (2.5 cm) per second.
2.
It may not be necessary to recover refrigerant if a loose fitting or a loose connection is causing a leak. Tighten loose con-
nection and perform performance check procedure. If necessary, add refrigerant to AC system (WP 0191 00).
3.
If repair of a leak calls for removal or replacement of a component, refer to WP 0192 00 thru WP 0197 00.
