The utopian vision of service-free air-conditioning systems has long been overthrown. Air conditioning mechanics these days accept the loss of refrigerant in virtually any system. It is not always the result of broken wires or an accident.
Even fully operational systems lose part of the refrigerant through rubber pipes, threaded connections, gaskets, etc. Such losses have a negative effect especially on modern air conditioning systems , which contain much less refrigerant than older systems. WAECO experts - a specialist in the field of professional air-conditioning service - point out some of the most commonly used methods, as well as their applications and limitations.
Leak detection with a UV lamp is done by injecting a special fluorescent additive into the air conditioning system. This method is suitable for detecting even small leaks and for leaks caused by vibrations it is the only one available. The condition for its effectiveness and safety for the system is the use of high-quality additives, specially developed for use with compressor oils and completely free of solvents.
The leak detection method is mainly used for initial diagnosis, as it only shows the presence of a leak, not its location. Leak detection is carried out by means of differential pressure, which in turn consists in creating positive pressure with nitrogen or negative pressure with vacuum, by an air conditioning service station. An automatic vacuum test is offered, for example, by the WAECO ASC 2300 G station available in the Autos network.
Finding very small leaks, on the other hand, is no problem for electronic leak detection. The forming gas method works similarly to it. It consists of 95% nitrogen and 5% hydrogen. Its disadvantage is the long duration of the process, testing the switched off system excluding the detection of leaks occurring only with the vibration of the running engine and the need to maintain constant ambient conditions, e.g. without drafts in the workshop. Ultrasonic leak detection, on the other hand, is possible even at high noise levels. A special device has a noise suppression system. A five-stage LED indicator informs about the intensity of the leak and additionally emits an audible warning signal. Whichever method you choose, leak checks are a must as it is illegal to fill faulty A/C systems. The R134a refrigerant in particular is perceived as dangerous and harmful to the environment. Regular checking for leaks is also in the interest of the vehicle owner, as it prevents damage to the compressor. In this context, leak detection is an important aspect of the work of all workshops servicing not only conventional air conditioning systems using R134a, but also filled with alternative refrigerants such as R1234yf or CO 2 .
