A/C Leaks

[bam]

Common problem. A/C not blowing cold enough. Re-charge, put dye in it - check for leaks. My techs tell me that in 90%+ of the cases, you won't immediately find a leak because it takes a while for the dye to work through the system and so you have to have them come back at a later date. This brings up a number of questions:
1) Do you charge diag the 1st visit, the 2nd visit or both?
2) Do you charge for full capacity of freon that you evac and re-charge once or both times?
3) If they have a service contract, you can't successfully file the 1st visit claim because you don't have a "failed part." How do you handle this?
4) Do you agree that 90% of the time, you can't find the leak on the initial visit? If not, what is the secret to finding the leak?

[robc]

I can't remark what I do, but what I would do:

1- No, not both. Charge on the first.
2- If you normally charge capacity, then I would say charge both times. Otherwise, capacity first, and actual amount of new freon on 2nd.
3- Of course there's ways to write the claim to get paid, but I would inform customer at write-up that NPF isn't covered by contract - so if NPF, it is their responsibility. Follow-up visits will likely be covered. I assume you have a normal, competitive A/C Diag fee that you can quote them
4- I agree, that is why you get the $$$ for what you did on visit one. The secret - GM is cool since they started adding dye at the factory. Short of that, I don't know. I always assume that there is a micro-amount of leakage past one of the o-rings, that might take many months to drain enough to affect performance again.

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** Rob, Editor Dealersedge/WD&S **
Help is only a message post away!
robc@dealersedge.com

[bcuster]

For a/c leaks we always use soapy water to test for leaks. I have found that dye does not always show a leak and if the system does not have dye in it, you don't have to go through the steps to add it. What we do is to check the system for any freon. If there is any in the system we recover it. Once the system is empty, we charge the system with nitrogen to about 150 to 200 psi. We spray all the fittings & hoses with soapy water ( MR. Bubbles works great ). With dye you have to add it to the system and allow it to circulate through the system and exit the leak area before you can find the leak and once you find the leak you must clean all traces of dye or you will never be sure it's fixed. By using nitrogen you find the leak quickly and you don't damage the system by adding contamination of any kind like moisture.

[spwilkins]

as far as the nitrogen goes, costly? fittings? do you have to evacuate the nitrogen or just let it out? I have heard of nitrogen on trucks - ok on cars? R12 or R134 or both?