I have some tips about leaky air conditioning systems.  You know how it goes; the refrigerant goes away, the air doesn’t work quite like it should, and yet you can’t see a leak. That’s because refrigerant is a gas and it escapes into the air.  Finding the leak is pretty simple if you have a kit like this.

This is dye that gets injected into the air conditioning system. The kit comes from Tracerline, it’s inexpensive and it’s very easy to use - just follow the directions.  Now once you have the dye into the system, you’d use the air conditioning for a period of time, then you would use a special light that comes with the kit.  This light has a bulb in it that makes the dye glow.  So you just move it around to different parts of the air conditioning system until you see this glowing dye and trace it back to where it came out of the vehicle. 

But maybe you do all that and you don’t find a leak.  What then?  Well it may be a leaky evaporator.  Now the evaporator is typically mounted up in the dash.  It’s buried, it’s expensive, it’s a real job to replace one so you don’t want a wrong diagnosis.  What you do is you run the car for a couple of hours with the air conditioning on, park it in a garage, and then put a drain pan underneath it.  Let it sit overnight, and some of the water will come out of the air conditioning drain.  Then you take the special light and shine it onto that water and if the water glows like this then you have found your leak, it’s in the evaporator!

Okay, we’ve got a positive diagnosis.  Now even if the air conditioning system isn’t leaking, another thing you have to consider is that evaporators get dirty so you have to clean them usually about once a year.  That requires a special product like the B-G Frigi-clean, it does an excellent job. 


If you have a question or comment, write to me.
The address is MotorWeek, Owings Mills, MD, 21117.