Leak detection - four methods to trace leaks
Leak detection is a hot topic in every A/C workshop – and not only for service on conventional R 134a A/C systems, but also for systems charged with alternative refrigerants, such as R 1234yf or CO2. There is an overview of the four most commonly used methods to trace leaks, plus some recommendations from our experts.
Learn more about the different techniques for detecting refrigerant leaks in vehicle A/C systems, and view the products required for each method.
A special, fluorescent additive is injected into the refrigerant circuit – either via the A/C service unit or manually. When the A/C components are illuminated with a UV lamp and viewed through yellow UV protection goggles, the leak appears brightly lit up. Visibility is ensured even where oilcovered engines are concerned and even at some distance. Unlike the forming gas method, UV leak detection is also suitable for tracing ultra-fine leaks. Where vibration leaks are concerned it is the only method available.
This method involves the production of positive pressure through nitrogen or negative pressure through vacuum by the A/C service unit. Leak detection through differential pressure is mainly suitable for the initial testing of strongly leaking or even empty systems. It only indicates that the system is leaking – not where the leak is. Testing is only possible with A/C service units that automatically stop when it is impossible to generate vacuum (e.g. all WAECO ASC service units). If the process continues without fault warning, you can be certain that the system has no leak and may be charged with refrigerant. The requirements of the Chemicals Climate Protection Ordinance are met.
Finding very small leaks is no problem for electronic leak detection systems. In some sections of the A/C system it is difficult though to apply the probe correctly, or at least very time-consuming.