Find car AC leak with AC leak detection kit
Find car AC leak with dye and UV black light
There are two ways to find a car AC leak: with an AC leak detector kit that uses UV dye, or with an electronic AC leak detector. Electronic leak detectors can cost several hundred dollars. But an AC leak detection kit costs around $75, less than a shop would charge you to install dye.
What you need to inject dye into your car AC system
If your car AC system is totally empty, you can remove the charging port valve and pour dye directly into the system. However, if you have any refrigerant left in the system, you’ll need to buy or rent a dye and oil injector tool or an aerosol can of dye. The Spotgun Jr Single Shot system shown below uses a caulk gun style injector tool with dye cartridges. Just attach the hose and quick connect connector to your system, load a cartridge and squeeze the trigger to force the dye into the AC hose. Here are three ways to inject dye in your car AC system.
The FJC hand turn oil and dye injector opens up and you fill it with dye or oil. Then you connect to your system and turn the handle to force the dye in. The Interdynamics Multi-shot dye for R-134a systems uses internal can pressure to force the dye into your car AC system.
Refill your car AC system with a full charge of refrigerant
It’s best to completely refill your system to find car AC leaks. Then

Uview 413010 Battery Powered, 6 LED Leak Detection Light
drive it for several days using the AC as much as possible. Then park the car in your garage and close the garage door so sunlight doesn’t interfere with the next step.
With the engine off, put on the UV glasses and shine the UV light on every connection and port. Go slowly because a small leak will have just a slight “tell.”

Here’s what a leaking suction port looks like under UV light
Or, buy a complete car AC leak detection kit

Tracerline (TP TP8647) car AC leak detection kit
©, 2015 Rick Muscoplat
Posted on by Rick Muscoplat