How to Easily Vacuum Your Car’s AC System Without a Pump
To vacuum AC system without pump on a car, first, connect an AC manifold gauge set to the low and high side of the system. Start the car and turn on the AC to the maximum. Then, use a vacuum canister kit to create negative pressure in the system. Allow the negative pressure to remain for a few minutes until you conclude that all moisture and air have escaped. Now close the high-side and low-side valves and turn off your car.