Anyone have advice for a mystery A/C leak?
Starting in 2011, my A/C system stopped blowing cold. In prepartion for a trip to AZ (from WA), I took it to the dealer to have it fixed. They said given my car's age (1998), it was probably going to have stay at the the shop a couple days, because it's never "just a leak" at that point. Anyway, they tested it, used the dye, let it run for 2 hours, etc, etc and the system held pressure.
A few months later (when I decided it was time to use the A/C again), I was lothe to discover it was not blowing cold. Took it to a new friend who works at the dealer here, he tested it, it held pressure, so he recharged it. Days later it was not cold anymore.
Some time later, I took it to school and worked on it with my teacher. We drained it, filled it with nitrogen; it held pressure. We filled it with dye. No leak. We used soapy water... no bubbles. We even used the little sniffer thingie. No leak. We replaced the low side Schroeder valve and over charged it to 2.1 lbs. Tested it. It blew 41 degrees with an ambient temp of 71.
Held pressure for a few months... and then blew ambient air. Took it back to my friend at the dealer, and we went through it together in his stall. We could not find any leaks. We replaced the high side valve. Held pressure (as usual). After about a week, maybe a week and a half, it's blowing hot (ambient Phoenix summer air) again.
I'm wondering what to do next... Anyone have some experience with anything like this?
Help greatly appreciated.
