Discharging & Evacuating System

Fig. 3 High And Low Side Schraeder Valve Locations:

1. Connect manifold gauge set and vacuum pump to high and low side schrader valves, Fig. 3.
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 step 2, proceed to ``System Charging.''
6. If vacuum loss is greater than 1 inch Hg., from level recorded in step 2, charge with with 1/2 lb. of R-12 refrigerant.
7. Leak test, repair leaks and re-test. Disconnect high side adapter from service port and check for vacuum loss before leak testing.