A/C High Pressure Relief Valve

[TonyM]

Anyone know where to source one of these bad boys? The small relief valve that threads into the manifold on the compressor. I've replaced everything else in my a/c system and there's still a leak. Sometimes the relief valve pops so I think it's the culprit and I want to put a new one on there.

[RAI]

I've had the same problem, but I think it's just the compressor.

Too high of a pressure has to be a clog, right?

[TonyM]

Well it depends. My pressure looks good with the gauges hooked up, where I was seeing trouble was driving in 100+ ambient temps with the FMIC. Airflow wasn't as great through the condensor so the pressure rose. In my opinion, I doubt it ever rose to levels high enough to be dangerous, but I do think that valve is shot and thus, was releasing freon. That and I think it probably stuck open a bit after relieving the pressure, thus continuing to leak freon out until it was all gone.

That's my theory as I've replaced every other component on the system. Since the manifold for the compressor carries over when you buy a new compressor, I'm thinking that valve is the culprit.

[MaxClass]

We had our A/C relief valve blow in Blyth, CA when it was 118 degrees on our way to San Diego from Vegas. Liked to killed us driving across the desert.
Turned out it was because someone had converted a '93 to use R-134 instead of R-12. 134 creates a lot more pressure combines with the extra heat and Ka-boom. The valve was history. DO NOT let someone convert your R-12 system to R-134 on these cars or you will run into the same problems.

Turns out most reputable A/C shops can find a replacement valve so check with them first. Don't let anyone tell you that you must replace the entire unit because you don't have to.

[TonyM]

94+ cars were 134A from the factory so no worries there.