TM 9-4120-370-14
TO 35E9-229-1
5-10. LEAK TESTING THE REFRIGERANT SYSTEM - Continued.
(f) Perform leak tests.
(g) If a leak is found, discharge and purge the system and repair leak. See specific instructions for
components to be removed.
(h) If a leak was not found and refrigerant22 was used to pressurize the system, see charging
(2) To pressurize a system that has been discharged and purged for leak testing with an electronic detector:
(a) Remove the hose connection protective caps from the high and low pressure service valves.
(b) Connect the hoses from a charging manifold to the service valves.
(c) Connect a drum of refrigerant22 to the center hose connection of the charging manifold.
CAUTION
Connect the refrigerant22 drum so that only gas will be used for pressurization.
(d) Open both unit service valves and the charging manifold valves.
(e) Open the refrigerant drum valve slightly and adjust as necessary to prevent formation of frost, and
allow system pressure to build up until the gages read 4050 psi (2.83.5 kg/cm2).
(f) Close the charging manifold valves and the refrigerant drum valve.
(g) Remove the refrigerant22 drum from the center hose connection.
(h) Connect a nitrogen regulator and cylinder of dry nitrogen to the center hose connection.
(i) Open the charging manifold valves and the nitrogen cylinder and regulator valve. Allow system pres-
sure to build up until gages read 350 psi (24.7 kg/cm).
(j) Perform leak tests, then discharge and purge the system, in accordance with paragraphs 5-7 and
paragraph 5-8 before performing maintenance, or
before evacuating and charging the system, as
appropriate.
(3)
Final leaktesting Always perform afinal Ieaktestafter performing any repair or replacement of components
before the air conditioner is reassembled and the refrigeration system is evacuated and charged.
5-13