http://www.buyautoparts.com/how-to/
To evacuate the ac system have 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. You can recharge the system after you've pulled the vacuum on the ac system.
@elflacuchin Well the minimum time wait period is ideally 30mins.
ThaSavor 4 months ago
i doubdt youl wait 30 mins to an hour
elflacuchin 6 months ago