If you car was built after 1994, it uses R134a refrigerant to power the air conditioner. Over time, most air conditioners will lose their refrigerant, and eventually they require a recharge. Fortunately, you can purchase a recharge lit from most auto parts stores, and complete the job yourself. Due to federal regulations, all air conditioners have a 13-mm quick disconnect low-side valve for recharging the AC in your car.
Thread the service hose onto the bottle of R134a, and close the valve on the service hose to crack the bottle open. Open the valve slightly to force air out of the service hose, and then close the valve.
Locate the low-side valve on the hose that connects the accumulator and the compressor. There are two hoses going to your compressor. The service hose will only connect to the 13-mm quick disconnect valve.
Remove the black cap from the 13-mm valve, and connect the service hose to the valve.
Turn on the automobile, and then turn on the air conditioner full blast.
Open the valve on the bottle to start the transfer of R134a from the bottle to the compressor.
Watch the pressure gauge connected to the service hose. Close the valve on the bottle when the gauge reads between "25 PSI" and "50 PSI."
Turn off the car, and disconnect the service hose. Place the black cap back onto the service hose.
