Air conditioning system failure is a common problem in many older automobiles. As an air conditioning system ages, systems can begin to lose pressure due to the failure of dried out gaskets or corroded metal. When the freon in the system leaks out, the air conditioning system will not be able to properly cool the air and eventually the system will stop working altogether.
When an air conditioning system begins to fail, the system should be physically inspected for problems. With the engine off and cool, a car owner should visually inspect all aspects of the system for problems. There are 3 major parts to an air conditioning system: the evaporator, the pulley driven compressor and the condenser which resembles a small radiator. These three major parts are connected by a series of metal tubes and hoses. All of these should be inspected for damage. Significant damage may indicate that the parts need to be replaced.
If no serious physical damage is found, the system pressure should be checked with a pressure gauge and compared against the manufacturer's recommended system pressure. If the system is found to be low, then there is a leak in the system. Auto part stores sell numerous leak detection products that contain a dye that will mark the location of the leak. Once the leak detection dye has been added and the system has been allowed to operate, a UV light is used to find the location of the leak. Any UV light can be used, but small ones are made for this purpose that can be used in the tight spaces around the air conditioning system components.
When the leak has been found, there are two primary ways of fixing it: mechanical repair or a stop leak product. Mechanical repairs are often time consuming and costly as after the part is replaced, the system pressure has to be brought to vacuum by specialized equipment to remove moisture. Stop leak products are much easier to use. These products are injected into the system and allowed to work internally. For example, BlueDevil's Red Angel AC Stop Leak is a stop leak product that will seal leaks due to damaged gaskets as well as leaks from corroded metal. When used according to manufacturer directions, stop leak products are safe to use and can result in significant time and financial savings.