Replace Pressure Relief Valve?

Friendly format provided to inquire about automotive a/c systems.
Archived Forum

Moderators: bohica2xo, Tim, JohnHere

Post Reply
mytown
Posts: 14
Read the full article
Joined: Fri May 25, 2018 6:04 pm
Location: Southern Illinois

Replace Pressure Relief Valve?

Post by mytown »

I recently charged the the ac system on my new-to-me 1997 Chevy Venture and used r134a that had UV dye in it. AC systems are new to me too. The system blew cold for only a few days. When I shined the uv light onto the connections and the components the only indication of leakage was where the 2 lines were connected to the top of the compressor. Frankly it looked kind of massive, that is, lots of green dye on the compressor. It appears to be leaking from the fittings on the top of the compressor and then down the sides of it. I have the two seals, but given the amount and the location of the dye I began to wonder if the seals didn't "blow out" because of either a bad pressure relief valve or perhaps a compressor control valve, both of which are screwed into the compressor. Could failure of either of these be related to the failure of the seals?
User avatar
bohica2xo
Preferred Member
Posts: 1170
Joined: Wed May 11, 2016 4:12 pm
Location: Las Vegas, NV

Re: Replace Pressure Relief Valve?

Post by bohica2xo »

It is unlikely the control valve has anything to do with the hose manifold leaking.

The seals at the hose manifold sometimes fail. On a 20 year old car it is likely that connection has been open at least once.

I would clean up the leak area carefully & watch to see exactly where the leak starts from. Was there a lot of oil on the compressor when you started working on it?

V5 compressors sometimes leak at the center joint in the case, called a "belly leak"

Just for reference:
messageview.cfm?catid=20&threadid=21972

Scroll down for pictures
mytown
Posts: 14
Joined: Fri May 25, 2018 6:04 pm
Location: Southern Illinois

Re: Replace Pressure Relief Valve?

Post by mytown »

bohica2xo wrote:It is unlikely the control valve has anything to do with the hose manifold leaking.

The seals at the hose manifold sometimes fail. On a 20 year old car it is likely that connection has been open at least once.

I would clean up the leak area carefully & watch to see exactly where the leak starts from. Was there a lot of oil on the compressor when you started working on it?

V5 compressors sometimes leak at the center joint in the case, called a "belly leak"

Just for reference:
messageview.cfm?catid=20&threadid=21972

Scroll down for pictures
Unfortunately I put little thought into looking for leaks when i added the refrigerant. I just happened to have a couple of cans of R134a w/UV dye lying around when I added them. I can't say how much oil was on the compressor at that time, plenty on it now. It appears that there is a fair chance that it is only the two seals, perhaps only one when I think about it since they share a manifold. Auto Zone has the vacuum and hoses/gauges for rent. The plan now is to replace the two seals and recharge using the dye, closely inspecting as I go, fingers crossed. I'm gaining confidence in bringing the ac back to life. Thanks for the reply and the link to the pictures.
Post Reply