TM 9-4120-371-14
h. Open, both unit service valves.
i. Run the vacuum pump until at least 29 inches of mercury, measured on the gage, is reached.
NOTE
Inability to reach 29 inches of mercury may indicate either a leak or a problem with the
pump.
j. Continue running the pump for one more hour, while observing the gage. If the gage needle moves back
and forth, you have a leak which must be located and corrected first.
k. Close both unit service valves.
l. Close charging manifold valves.
m. Stop vacuum pump.
n. Disconnect pump from center hose connection,
o. Go to paragraph 5-11, charging the refrigeration system.
Supplies: Dehydrator
Refrigerant 22 (Drum) (item 10, Appendix E)
After the system has been satisfactorily evacuated, it must be fully charged with refrigerant-22.
