Replacement Freon in an Air Conditioner

If the air conditioner in your car is no longer blowing cold air, it may be time to recharge it with replacement freon. Freon is the chemical refrigerant that is used in auto air conditioners to cool the air that is pumped through the system. The freon in the air conditioning unit eventually runs out. Replacing it yourself can save a lot of money that you would otherwise pay to an auto mechanic.

The way in which an air conditioning unit works is rather complicated, but simply put, hot air is pulled from the inside of the car and expelled to the outside of the car. Air is then pulled through the car air conditioning system, cooled and pushed into the car's interior through the air conditioning vents.

Cars made prior to 1993 use R12 freon, an environmentally damaging product that is no longer available to the general public, but can be acquired and used by professional mechanics who have access to the required environmental waste disposal process. Cars made after 1993 use R134a freon, which is readily available at auto repair supply retailers.  

Note that R12 and R134a refrigerants do not mix, so do not attempt to recharge a car that has a pre-1993 air conditioning system with R134a freon. If you have a car that was manufactured prior to 1993 and are having problems with the air conditioner, it is best to take it to a professional mechanic to diagnose the problem and have the system recharged correctly.

With the right supplies and a little instruction, replacing air conditioning freon is an easy do-it-yourself project.

Supplies Needed:

• Replacement Freon
• Owner's Manual for Car

Step 1—Using your owner's manual, locate the hoses to the air conditioning compressor in your car. Attach the shorter hose to the can of replacement freon but do not completely tighten the connector.

Step 2—Open the valve on the freon can to release air from the system. Tighten the connection and valve.

Step 3—Start the engine and and turn the air conditioner on high. Holding the freon can upright, slowly open valve on the short-end manifold.

Step 4—When the can appears to be close to empty, slowly close valve on the short-end manifold. Carefully remove the can from the hose.

Step 5—Repeat Steps 1 through 4 as needed until system is recharged.