TM 9-4110-258-13
5.11
LEAK TESTING THE REFRIGERANT SYSTEM.
This task covers:
Testing
INITIAL SETUP
Tools:
General Safety Instructions:
Nitrogen Regulator
WARNING
6, Section III, Appendix B
Never pressurize refrigerant lines with
Materials/Parts:
oxygen, mixture with oil could cause an
Nitrogen
explosion.
11, Appendix E
Refrigerant R-134a
The pressure in a nitrogen cylinder can
12, Appendix E
exceed 2000 psi. A nitrogen pressure
regulator should be used at all times to
Equipment Conditions:
avoid personal injury.
Service manifold installed (para 5.7).
Nitrogen is an inert gas that can cause
suffocation and must be discharged in a
well ventilated area.
Testing.
NOTE
To perform leak test, it is necessary that the system be pressurized with a proportion of
refrigerant gas.
The electronic gas tester is highly sensitive to the presence of a minute quantity of gas in the
air, and is quite effective in the detection of small leaks. However, due to rapid dispersion of
refrigerant gas into surrounding air, difficulty may be encountered in pinpointing large leaks.
The detector must be used in a well ventilated area but draft free area. Use procedures
contained in TM 9-4940-435-14, "Leak Detector, Refrigerant Gas".
(1) To pressurize a system that has some refrigerant charge.
(a) Connect the charge hose to a refrigerant cylinder containing refrigerant R-134a set to deliver gas only.
(b) Check that service manifold vacuum valve is closed.
(c) Open the service manifold compound gauge, pressure gauge, and charge valves.
(d) Open refrigerant cylinder valve and pressurize system to 100 psi (7.1 kg/cm2).
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