Using Charging Station

On systems using R-134a refrigerant, use a charging station designed for R-134a refrigerant systems.

A vacuum pump is built into the charging station that is constructed to withstand repeated and prolonged use without damage. Complete moisture removal from the A/C system is possible only with a pump of this type.
1. Connect charging station and discharge system as outlined previously. System must be completely discharged prior to evacuation. If pressurized refrigerant is allowed to enter vacuum pump, pump will be damaged.
2. Reconnect vacuum hose to vacuum pump and ensure that vacuum control valve is closed.
3. Fully open low and high pressure control valves.
4. Connect station to a suitable voltage source and operate vacuum pump.
5. Slowly open vacuum control valve and observe low side compound gauge. If system does not "pump down" to 28 - 29-1/2 inches Hg (at sea level) within approximately 5 minutes, recheck connections and leak test system.
6. Continue to operate vacuum pump for 15-30 minutes, longer if system was open for an extended period of time, then close all control valves and stop pump.
7. Check ability of system to hold vacuum. Watch low side compound gauge and ensure that reading does not rise at a rate faster than 1 inch Hg every 4-5 minutes.
8. If system fails to hold vacuum, recheck fittings and connections, and leak test system.
9. If system holds vacuum, charge system with refrigerant.