Auto A/C Terms - Glossary
Leak Detector

One of the most common failures on automotive A/C systems is the loss of refrigerant through leaks. Service technicians will utilize a leak detector in order to help find the leaks. Leak detectors are devices designed to pinpoint leaks.

However, the process of leak detection is far more complicated than just ‘point’ a leak detector at the A/C system. The standard leak detector is known as an electronic leak detector. As the A/C components are ‘traced’, the sensing head of the leak detector is sampling air and sounds an alarm when it detects the chemical components of refrigerant.

Other leak detection methods such as UV dies should also be considered as part of the leak detection process. Once installed into the A/C system, the dye will be circulated with the refrigerant oil. When it reaches a leak, the dye will be visible with the help of a black light or UV light. (Ultra Violet light).

The absolute best method of finding all the leaks in an A/C system is to utilize high pressure nitrogen. Understand that all components of the A/C system are manufactured to withstand certain pressures, regardless of whether they are high or low side components. Nitrogen will not cause good A/C components to fail, as long as you follow certain rules. Only use nitrogen to a maximum of 200 psi. At that pressure, all A/C system leaks will be exposed and easily detected with external leak detection methods.

Nitrogen leak testing is far superior to using refrigerant, as with refrigerant, you are limited to pressures of about 80 or 90 psi. (You perform leak testing with the engine off. Static pressures of refrigerant mean that you will only ever attain 90 or 90 psi. of pressure). With nitrogen, you are able to test with higher pressures and find all the leaks in any A/C system.