Figure 5-4. Evacuation of Refrigerant System
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.
Close charging manifoid valves.
Close both unit charging valves.
Stop vacuum pump.
Disconnect pump from center hose connection.
Go to paragraph 5-14, charging the refrigeration system.
After the system has been satisfactorily evacuated, it must be fully charged with Refrigerant-22.
Never introduce liquid refrigerant into the low pressure (suction) charging valve.