TM 9-4120-357-14
Section III.
GENERAL REFRIGERATION SYSTEM MAINTENANCE
5-4.
Refrigeration System.
Maintenance of the refrigeration system consists of replacement of components, cleaning the system, purging air and
moisture from the system, and recharging tile system with refrigerant. Removal and installation of major components
5-5.
Testing for Leaks.
Whenever bubbles appear in the sight-glass liquid indicator after the air conditioner has been running for some time, or
whenever a component of the refrigeration system has been replaced, the system must be tested for refrigerant leaks.
Three methods are available for detecting leaks; the electronic leak detector, the Halide torch, and the soap bub-
ble method.
The preferred method is to use an electronic leak detector, GE type H-10 or equivalent.
CAUTION
The electronic leak detector and the halide torch are sensitive to the presence of
refrigerant gas in the atmosphere. When refrigerant gas is present in the atmos-
phere of the work area, false indicators can result. Use in a well ventilated but
draft-free area.
a. Electronic Leak Detector. Turn the electronic unit on, and slowly pass the probe around all points of the re-
frigeration system at which a leak could exist. Depending upon the type of detector used, a leak will be indicated by an
audible signal, a light, or by meter deflection.
b. Halide Torch. Turn on the gas from the cylinder and light the torch. Adjust to obtain a stable, light-blue flame.
Pass the open end of the sensing tube slowly around all locations at which a leak could exist. A small leak will be indi-
cated by the flame turning from blue to green. A large leak will be indicated by the flame turning from blue to indigo with
a red tip, or the torch may be extinguished.
c. Soap Solution. Brush soap solution on all possible points of leakage, and watch for bubbles. Follow a definite
sequence to avoid missing any points that should be tested. Wipe the solution from all joints, and mark any pint at which
a leak is found.
5-6.
NOTE
In accordance with Environmental Protection Agency regulations, refrigerants cannot be
discharged into the atmosphere.
A refrigerant recovery and recycling unit must be
Operation of the recovery/recycling unit must be by AUTHORIZED PERSONNEL ONLY.
Whenever a leak is detected or a refrigeration component must be replaced, you must discharge all gas from the refrig-
eration system. To do this, connect and operate a recovery/recycling unit in accordance with the manufacturer's instruc-
tions.
5-7