Leak detection dye for AC

[brmurph]

The dealer installed a life time guarantee AC compressor on my 98 Deville and apparently added dye as I have a leak and see the dye (with a black light) all over the compressor (so hoping to get a free replacement :-). I also see a very light trace of dye around most of the AC lines (and some other parts of the motor) as well. For those that use dye is this normal or do you think I most likely have multiple leaks? Its light enough that I originally did not see any dye from the top with a quick look but upon a second closer look I did see the trace of dye (again with the black light). The compressor leak is obvious as you can see the dye pretty thick.

Thanks in advance.

[Cadillac Jim]

The procedure is to clean off the compressor and restart the car and watch with blacklight to see *exactly* where the leak is. It probably is in the compressor seals and is coming out the seal where the shaft exits the case - which would require a replacement compressor, but it could be a fitting or something easily replaceable.

I had something similar happen with my 1997 ETC. The clutch started slipping a few months after the new compressor was installed. It kept getting worse and I eventually let them replace it free. I think all it needed was a clutch clearance adjustment, but that is something that they don't authorize techs to do. And, they don't replace compressor clutches, either - the compressor and clutch are replaced as a unit.

This kind of thing is one of the legitimate reasons to go for the Goodwrench warranty on an old car. If you plan on driving it for a long time, the Goodwrench warranty can be worth the extra cost. Most exchange compressors are warrantied for periods ranging from 90 days to a year.

[KHE]

There should not be dye at the connections - I would use some dye cleaner solvent and clean the areas, then run the car for a day or two and re-inspect the areas.

The shaft seal is not typically the culprit in these compressors - it is a double lip teflon seal that is very durable. The problem area is the case seals on the compressor will leak over time due to corrosion of the aluminum ends of the compressor. The corrosion creeps in around the o-rings and the case o-rings no longer are able to seal. They can be resealed with a $20.00 seal kit plus a GM shaft seal for a total of about $50.00 but in this case, the compressor is under warranty so they'll probably replace the unit.

[barczy01]

Check the low pressure switch and or oring with it. They often leak. Evaporator core?

[KHE]

Check the low pressure switch and or oring with it. They often leak. Evaporator core?

Evaporator leaks are pretty rare on these cars but if the system has dye in it, the easiest thing to check the evaporator is to look at the condensate drain for traces of dye.

[brmurph]

Thanks guys.

[Cadillac Jim]

[brmurph]

I thought about picking one of these up. Any personal experiance with these? Do they work pretty well ?

[Cadillac Jim]

Actually, the one I used many years ago was a special attachment for a propane torch. The electronic sniffers have been around for decades. The reason that I posted the photo (with link to its page on Amazon, offering it and several others for about $25) is that I thought that it was odd that a GM dealer that replaces compressors would not use a sniffer to verify that a system was leak-free before releasing it.

[KHE]

I've never heard of that brand. See if there are replacement parts available - particularly the heated diode sensor as that is what will go bad. If replacement parts aren't available, count on it being a throw-away device that might only be good for one use.

[Cadillac Jim]

I never heard of any of the brands of electronic Freon sniffers that I saw on Amazon. I clicked on the link I provided with the photo and the tech blurb says that it detects *any* Freon, SF6, and that its Freon sensitivity is a leakage rate of 6 grams per year. A hint that it *does* use a heated diode is a warm-up time of six seconds.

I suppose that a replacement diode and perhaps other parts would be available, but at $27.99 with free shipping, the $25 price range sniffer strikes me as a throw-away (good for life for the DIY guy but not sturdy enough for an A/C shop). A Snap-On or other brand made to take continuous usage every day would be more expensive but would be designed and built to have serviceable parts.