If your BMW's air conditioning isn't quite as cool as it once was, a simple recharge may be all that's required to bring the temperature back down to a comfortable level. The advent of all-in-one consumer recharge devices makes it possible to test and refill your air conditioning without the assistance of a professional. In addition to the required R134a refrigerant, many kits also contain agents to help seal minor leaks in the system. A UV-reactive dye may also be included to help identify the location of any leaks.
Open the BMW's hood. With the engine off, locate the topmost metal air conditioning line. This can easily be located by following the tubing that runs from the compressor. Find the service port, which extends out from the air conditioning line and has a plastic cap on top. Unscrew the cap.
Connect the hose of the recharge kit by screwing it onto the service port. Turn the engine on and set the air conditioner to "Max A/C". Return to the engine bay and check the pressure gauge on the recharge kit. If the needle is in the red or yellow zone, the refrigerant levels are low enough to require a recharge.
Hold the trigger down for a few seconds, then pause to check the pressure gauge. Repeat this process until the needle is at least in the middle of the green zone. Turn the engine off and disconnect the recharge kit. Replace the cap on the service port and close the hood.
