A/C R-12 / R-134A Conversion

[JNR]

Well, good to hear there aren't any problems.

So basically, you don't have to change over existing 'major' equipment like compressor and condensor, etc., so long as it's flushed out real well?

I'd still like to look into (someday) changing the 'velles compressor with a smaller unit and maybe even looking into cleaning up the firewall, while retaining the rest (controls, vents, etc.); I'm sure somebody has a kit and/or sells those parts...

I always like an A/C to work if it came equipped and good to hear the options.

 

I JUST got mine working yesterday. What a PITA! Unfortunately, my compressor and system sat open during a lengthy engine rebuild. When recharged it wouldn't make much pressure. I swapped on a used compressor and that one made 0.

Off to get a GVR compressor. The clutch assembly is near impossible to get from anywhere. I got a remanned compressor only and changed most of the o-rings, expansion valve & drier. I had to install the old clutch and for some reason the air gap was WAY too big. I had to do a lot of grinding to get it down to 0.030 air gap.

This compressor worked at first but then wouldn't accept the second can of freon. Argh!!! Something went wrong. /ubbthreads/images/graemlins/frown.gif

Swapped in another compressor (#4) & it now works!!! I blew out all the lines and used PAG 46 this time. I used Ester 100 the first time because it's supposed to be more compatible with the old oil. I blew out a lot of foamy oil.

If your system works a little and you want to change over to 134, I'd suggest you get a new drier and a flush kit. The PAG oil says it will work if you blow out more than half the old oil. Swapping in a new drier will get rid of ~3-4 oz. of the old stuff. Total system capacity is ~8-9 oz.

I have a couple more R12 cars to fix/convert so bought a pro series dual gauge set and the air compressor venturi type Harbour Freight vacuum pump. That thing actually works!

 

A few years ago I had a guy tell me it was about $100 for a refill of R12, just for the R12. Compared with 134a was about $20. So to get it switched over it is the same or just a little more than getting R12. But, once it is switched, you can do everything yourself. A can of 134a is only $6-7 at any autoparts store, and anyone can get it. I would get it switched if it were me. Our cars are fine with the switch, my VR4, GSX, and my old Jeep were all switched over and never any problems with 134a. I believe it was in 1994 that all cars were switched, but some manufacturers switched in the early 90's. Hope this helps.