The AC recovery/recharging machine has a built-in electric vacuum pump that pulls an excellent vacuum on the system without having to connect external hoses or manifolds. Pulling a vacuum on the AC system prior to recharging it with refrigerant is necessary to remove all of the moisture from the system.
The boiling point of water is lowered to 70 or 80°F when a good vacuum is applied to an AC system. If any moisture is left in the AC system, it can mix with the refrigerant and acid will form and cause damage in the system. Below are the steps for vacuuming the system with the AC machine.
Each AC system that has been opened for repair or that has had a leak should be vacuumed for at least 30 minutes to remove all of the air and moisture from the
