AC Charge

Pulling Vacuum

Because the system isn't charged, valves aren't overly important, but it's a good idea to follow the procedure anyway just as a best practice.

1. Close HI/LOW Valves on both the gauges and the lines and then connect Hi/Lo lines to the car
2. Open the HI/LOW valves on the lines (NOT the gauges)
3. Connect Yellow Line to Vacuum Pump and Turn On
4. Open Both Hi/Low Valves and Both Should Go Near -30 inches of mercury
5. Vacuum Down System for 30 minutes
6. Turn off Vacuum Pump and wait 30 minutes
7. Verify that gauges are still showing near -30 inches of mercury and that pressure does not increase
8. If not, check for leaks. If so, run vacuum pump for 45m to 1hr longer
9. Close both Hi/Lo valves, turn off pump, and disconnect yellow line

Adding Freon

1. Connect adapter to 134a freon can
2. If needed, add dye and oil to yellow line
3. Connect yellow line to freon can and pierce the can and open the valve
4. Purge yellow line until freon comes out
5. Start the car, turn AC on, and turn fan to low
6. Open only the LOW side valve. Low side pressure should increase to 50+ psi
7. Listen for the compressor to engage. If it does, the pressure should immediately drop to around 10psi and the high side pressure should increase
8. Shake can periodically and notice if refrigerant is still moving through watch glass. Wait until can is empty.
9. Close the LOW side valve completely and close the refrigerant adapter valve
10. Add the second can, pierce it, and open the valve
11. Purge the yellow line of any air until freon comes out
12. Slowly open the LOW side valve to restart the charging. Do not open all at once or it could slug the compressor.
13. Once the can is empty or the car is at the proper charge, close both valves on the guages
14. Close both HI/LOW valves on the line connectors and disconnect them from the HI/LOW sides of the car
15. Close the refrigerant can valve completely, and disconnect the yellow line