Detection for Auto A/C Systems
are several different methods to find leaks in auto A/C systems. For
the most part, all of the different methods are reliable. More important
than the method used is understanding how to use the leak detection method
properly. The most common methods for finding leaks in automotive A/C systems
Dyes and UV Leak Detection Lights (Black Light): Typically, the dye is
injected into the system or added when the system is open. The UV dye will
fluoresce (or glow) under UV light exposing the area of the leak. The dye
is an excellent method of pinpointing the leak. However, it also relies on
you being able to visually inspect all the components of the A/C system.
In today's systems, components like evaporators are difficult to inspect
visually without removing them. Additionally, to get the most effective and
accurate results from UV dyes, the light used should be producing true UV
light; not 'near UV' or 'blue' light. Only true UV light will fluoresce the
dye properly. Lights that are promoted or sold as 'near UV' of 'blue'
lights are little better than toys. Additionally, when using true UV lights
properly, there is no requirement for the yellow UV enhancing glasses.
Leak Detectors: Almost all electronic leak detectors rely on
a sample of air to detect the refrigerant or some component of the refrigerant.
Typically, these tools are very accurate and can, in some cases, find
leaks that are considered to be 'normal'. As an example, compressor
shaft seals typically leak because they run dry of oil. The refrigerant oil
or A/C compressor oil is required to maintain the seal. Electronic leak
detectors frequently detect shaft seal leaks that can not be repaired with
replacement seals. Additionally, the calibration of the leak detector is
very important to the accuracy and reliability of the leak test. You
should always follow manufacturer's instructions and keep the sensor tips
clean and free of debris.
Leak Test: Although not the most common method of leak detection, it
is one of the most reliable! Regardless of what other 'writers' have said,
professional auto A/C service technicians understand the importance of using
Nitrogen. What's best about nitrogen is that it allows the service technician
to perform the leak test at operating pressures. Adding refrigerant and
completing the leak test at 70 p.s.i. will not find all the leaks on the
high pressure side of the A/C system. It's very common for an A/C condenser
to leak at 150+ p.s.i. But finding that leak with only 70 p.s.i. of refrigerant
pressure could prove impossible. With nitrogen, the system can safely be
pressurized to (up to) 200 p.s.i. That allows a complete leak test at
operating pressures in order to accurately diagnose both the high
and low pressure sides of the system. The use of soap like 'bubble leak
check' fluids and electronic leak detectors in conjunction with nitrogen
makes for the ideal complete, professional leak detection. Find all the
tips and tricks
to using nitrogen as a reliable method of leak detection for all automotive
the method of leak detection is important, it is equally important to
understanding how these systems really work and what you can do to make them
more effective. In fact, many of the tips and tricks are never published
in the manufacturer's instructions or in auto A/C service manuals.
for Auto A/C systems reveals all the tricks the pros use every day for
accurate and reliable leak detection of any auto A/C system on the road!