How to Add Freon to a Maxima

by Craig Woodman
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Automotive air conditioners lose efficiency over time. This is because an air-conditioning system will lose a small amount of refrigerant, or freon, each year. Over the course of a few years, the system will lose enough that you'll notice the air is not as cold as it should be. Adding an amount as small as a 1/2 pound can help restore air conditioner function.

Step 1

Raise the hood of the vehicle. The air-conditioning system will have two service ports: a high side and a low side. The low side service port will have a blue cap on it. Both ports are located near the top of the engine compartment and should be visible.

Step 2

Remove the blue cap from the low side service port. Inside is a schrader valve, which looks similar to a tire valve that you use to inflate tires. The cap is threaded onto the line and must be unscrewed.

Step 3

Place the side of the low-pressure hose with the valve over the top of a can of refrigerant. Lock it in using the handle or screws that come with the hose. Don't turn the valve yet. Thread the other end of the hose over the low-pressure service port, tightening it by hand.

Step 4

Start the engine of the vehicle and turn the air conditioning to high. Turn the valve on the low-pressure hose clockwise as far as it will go to pierce the top of the can. Turn it counterclockwise to open the valve and allow the refrigerant to flow into the system. Shake the can gently as you do this and throughout the charging process. In about one minute, the can will be empty.

Step 5

Close the valve on the low-pressure hose by turning it clockwise. Remove the low-pressure hose from the schrader valve and replace the cap. Check the operation of the air-conditioning system after a few minutes.

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