My RX is in the shop to fix an A/C problem. I do not trust the shop ( long story ). They are telling me that a pop off valve ( pressure relief valve ) on the back of the compressor has blown, and that it must be replaced and the system re-charged. My question is - is there such a valve, as I can find no reference to it in the workshop manual.

 

Hmmmmm, that is a new one to me.....
There are high and low pressure shut off switches in the system, but a pop-off valve?

I would just ask them, "Exactly where is this valve at, show me how you know it is "popped", show me a new one, show it to me in my service manual, please....."
I'll bet they find a different problem after this, but I would tell them "no thanks, I am going somewhere else" as a/c repair shops are recognized as one of the most likely to rip people off, now that R-12 is hard to find and fewer people are doing their own a/c maintenance.

When my a/c started acting up on my Audi, the first shop I took it to quoted me $800 as a minimum for them to look at it and fix it. When I pressed for details as to WHY it would be so much, they started giving me the runaround, so I just left.

 

Thanks for the info. These guys have been giving me the run around for weeks, they told me the A/C was not cycling because the pressure switch in the ECU was bad. The pressure switch is not even in the ECU! As you said, I think I will ask them to show me the valve.