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TM 10-4130-239-14
5-6.
REFRIGERATION SYSTEM SERVICE - LEAK-TEST.
This task covers:
Leak-testing
Equipment
Condition
Para
Condition Description
2-8
Engine stopped.
4-15
Housing removed.
Tools
Tool Kit, Service
Refrigeration, item
5, Appendix B
5-8, Steps
System charged to 50 psig
1-3
minimum if needed.
Materials/Parts:
Dry nitrogen, item 11, Appendix E
Bubble, liquid type, item 7, Appendix E
R-12 Refrigerant, item 24, Appendix E
1.
Attach nitrogen tank to manifold gauges.
2.
Open valve and apply 300 psig to refrigerant system.
NOTE
Two leak detection methods are recommended
depending upon the estimated size of the leak.
Different techniques are used for detection.
Under certain conditions a large leak may mask a
smaller leak and both techniques may be required.
The larger leak is searched for first.
Regard-
less of the size of the leak, the system must now
be pressurized with refrigerant vapor, to the
pressure of the refrigerant tank, using the
charging manifold described previously.
The
pressure obtained will be the vapor pressure of
R-12 and a function of the ambient temperature,
probably in the order of 50-140 psig. Turn off
the valve on the service manifold.
3.
To detect large leak start with the liquid bubble type leak
detector, and apply moderate quantities at each SAE fitting,
tubing or hose connection.
Leaks greater than 0.04 cc per hour
will appear as a series of bubbles.
5-12
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