How to Add Freon to a Car Air Conditioner

When your car's air conditioner doesn't seem to be blowing cold air anymore, you may need to add Freon to the air conditioning system. Mechanics can charge hundreds of dollars to do this, but you can do it for much less if you know how. Learn how to add Freon to a car air conditioner by following these steps.

Difficulty: Moderate

Instructions

1. Attach the recharging hoses to your system. The hoses from the gauges attach to the compressor of your air conditioning system. Attach the shorter hose to the can of Freon.

2. Open the valve on the can for several seconds to purge the air from the system. Tighten the hose connection again and close the valve.

3. Start the car's engine and turn on the air conditioner on HIGH. Allow the refrigerant to enter the system by slowly opening the valve for the low-side manifold. Make sure to hold the can upright, not allowing any liquid Freon to enter the system.

4. Close the valve and remove the hose from the low-side fitting after the can is empty. Be careful when removing the can as there is still some Freon in the can.

5. Repeat these steps if your system needs more than one can of Freon. Adding too much Freon is worse than not having enough and can damage the air conditioning system.

Tips & Warnings

• Always wear eye protection because the refrigerant instantly freezes any type of liquid.
• Protect your skin from the coolant as it will cause frostbite.
• Do not attempt to add Freon to a car made prior to 1993 or to one that uses R-12 for the cooling system. This is illegal and can only be done by a certified mechanic.
• Adding any coolant to your air condition system can be dangerous if done incorrectly. These systems are under pressure and if a fitting is connected to the can of refrigerant incorrectly it can explode, causing injury or even death.