http://www.discountacparts.com/car_air_conditioning.htm
Evacuating the ac system should be done with both of the couplers installed and both of the valves completely open. The low side gauge should start to draw a vacuum. You should leave the vacuum on for 30 minutes to an hour. After you pull the vacuum on the system it's ready to be recharged.
bravo cant wait to do this to my stang been blowin hot for years
womackke 1 year ago