Discharging & Evacuating System

Fig. 3 High And Low Side Schraeder Valve Locations:

DISCHARGING
Before removing or replacing any of the A/C refrigerant lines or components, the refrigerant must be completely recovered using any A/C refrigerant recovery and recycling system. Always check the A/C system for pressure with a manifold gauge set to determine if refrigerant is present in the system. Performing recovery on an A/C system that is exposed to the atmosphere as a result of a leak, would allow the recovery station to pull only air into the tank.

EVACUATION
1. Connect manifold gauge set and vacuum pump to high and low side Schraeder valves. Refer to Fig. 3. for valve locations.
2. Turn vacuum pump on and slowly open high and low side valves to pump. Allow system to evacuate for 20-30 minutes. Note vacuum gauge reading.
3. Close high and low side valves. Shutoff vacuum pump.
4. Watch low side gauge for vacuum loss (1-3 minutes).
5. If loss is less than 1 inch Hg., from level recorded in previous step, proceed to "Charging System.
6. If vacuum loss is greater than 1 inch Hg., from level recorded in previous step, charge with 1/2 lb. of R134a refrigerant, depending on system type.
7. Leak test, repair leaks and retest. Disconnect high side adapter from service port and check for vacuum loss before leak testing.