TM 9-4120-402-14
5-16. EVACUATING THE REFRIGERANT SYSTEM. - continued
(5)
Start vacuum pump.
(6)
Open service manifold high pressure gauge, compound gauge, and vacuum valves.
(7)
Run vacuum pump until at least 29 inches of mercury is measured on compound gauge.
NOTE
Inability to reach and hold 29 inches of mercury may indicate either a leak or a problem with the vacuum pump.
(8)
Continue running vacuum pump for one more hour, while observing the gauge. If gauge needle moves back
and forth, you have a leak which must be located and corrected. (See paragraph 5-15.)
(9)
Close unit DISCHARGE and SUCTION SERVICE VALVES.
(10)
Close service manifold high pressure gauge, compound gauge, and vacuum valves.
(11)
Stop vacuum pump.
(12)
Disconnect the vacuum hose from vacuum pump.
(13)
5-46