Repairing Refrigerant System Leaks.

TM 5-4120-339-14

(3) If refrigerant system has been opened and the refrigerant removed, proceed to step (5).

(4) If refrigerant system has not been opened, check system static pressure on suction side and on

discharge side of compressor. If pressure on both the suction side and the discharge side is at least 100 psig (7.0 ks/

mc2), proceed to step (6). If the pressure on both the suction and the discharge side is less than 100 psig (7.0 ks/mc2),

proceed to step (5).

(5) Add vaporized refrigerant to both the suction side and the discharge side of the compressor through the

service valves until the suction pressure and the discharge pressure are at least 100 psig (7.0 ks/mc2).

(6) Using available leak detector, check areas of the refrigerant system showing collected refrigerant oil and

associated accumulated dust. Pinpoint and tag each leak found.

d. Repairing Refrigerant System Leaks.

(1) Refer to paragraph 4-6 and release refrigerant from the system. Leave the service valves open.

(2) If the leak is to be brazed, proceed as follows:

(a) Connect a source of vaporized nitrogen to the service valve closest to the leak.

(b) Release the nitrogen into the system while brazing the leaking area.

(3) If the leak is in a fitting, proceed as follows:

(a) Remove the fitting and associated component from the system.

(b) Clean the fitting.

CAUTION

Use care in applying leak lock or high vacuum grease so that when the fitting is

installed, none of the material gets inside the refrigerant system.

flare nut fittings.

(d) Apply leak lock (National Stock Number 4030-00-999-6313) to the threads of threaded fittings.

(e) Install and tighten the fitting and associated component.

(4) Repressurize the system with vaporized refrigerant to get 100 psig (7.0 ks/mc2) on both sides (suction

and discharge) of the compressor.

(5) Using available leak detector, verify that the repaired area is no longer leaking. Repeat steps (1) through

(5) if repaired area is still leaking.

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