While waiting for the warmer weather I've been rebuilding a few things on the bench inside the basement. Finished the carburetor, distributor, and the a6 ac compressor. I have the VIR all apart. I also have another VIR that was attached to a used evaporator that I bought. One of the VIR's is stamped with an "E" below the sight glass and the other one is not. The original one that came with the car does not have the stamp so I was going to reuse that unless the "E" stamped part is a better part? I was planning on converting to R134 but I'm not sure that is the way to go after reading some reviews of people who have done it. If I do decide to go back to R12 I'll need a full charge since the system has been O/S for many years. When I rebuilt the compressor I used PAG oil on the O rings and seals but I didn't yet fill the reservoir, just a small amount to lube the o rings. Will I have to disassemble the compressor and wipe it clean if I use R12 and Ester or is a trace amount no harm? There isn't a whole lot of information on rebuilding the VIR on the internet. I have read that you can adjust the POA for use with R134 but other's have said that the internal POA is not adjustable. I did find a slotted screw on the bottom of the valve but I'm not sure if that is what they are referring to.

 

teamo,
Save yourself a whole lot of grief, go to eBay and buy the VIR eliminator kit. The VIR was a poor design and it didn't take GM too long to realize this and dump it. If you're converting to 134 you'll find the system works much better with the eliminator. I converted the entire system in my '73 last year and posted an easy "follow along" thread. I'll find a link to it and repost here for you. I'm in the California desert with temps in the triple digits and a year later my system still cools the car just fine.
Greg

 

teamo,
Here is the link with pictures. Sorry, thread was started by Sunnyd1960. I thought I had started it. But all the info is there, just scroll down a bit. The whole thread is not very long.
https://www.corvetteforum.com/forums...liminator.html
Good luck, Greg

 

I wasn't sure that eliminating the vir was the way to go. I've read some negative reviews of people who have done it. Good to hear that it worked out for you. I'll look at ordering those parts this week. Thanks for the help.