During the lifetime of your Ford F-150, the air conditioner may begin to blow warm air; this is a sign that the air conditioning unit needs to be recharged with refrigerant. A mechanic can do the job, but that can be rather expensive. An alternative is to purchase a can of R134a refrigerant with a hose included and recharge your system yourself. Once you have followed the steps and recharged your system, you'll enjoy cool air in your truck once again.
Allow the Ford F-150 to cool for at least 30 minutes before you begin any work under the hood.
Locate the service fittings on the air conditioning system. Refer to your owner's manual for exact location. The low-side fitting is on the suction hose running from the accumulator to the compressor. The high-side fitting is on the hose from the compressor to the condenser.
Connect the recharge service hose and valve to the refrigerant can. You can purchase the R134a refrigerant at any local auto shop or Walmart. Instructions can also be found on the refrigerant can.
Turn the valve on; this will puncture the top of the can. Once the valve has been turned on, there will be a release of air and coolant. Close the valve to prevent the loss of extra refrigerant.
Connect the service hose, while holding the can upright, to the low-side fitting.
Start the engine and turn the air conditioner to the highest setting. It helps to have another person assist with this step so one of you can check the refrigerant can. Open the service hose valve to allow the refrigerant vapour into the air conditioning unit. If another person helps, he should feel the air getting colder inside the vehicle, if not, slide into the F-150 and check to see if the air is getting cold.
Charge the air conditioning unit until the can of R134a is empty or until the air stops getting colder. Close the hose valve on the refrigerant and shut off the engine. Once the valve has been closed, disconnect the can from the low-side fitting. This process may be repeated anytime the air conditioning needs to be recharged.