My 67 still has the original AC unit on it. It was working up until about 4 months ago. My compressor needs to be replaced so I am thinking of converting the system to 134A refrigerant.

Has anyone made the conversion?
Problems?
Helpful hints and advice?
Should I just spend the $ and use R-12?

Stephen

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67 RS/SS 350 700R4
69 SS clone unfinished
72 454 Weekend Racer

I did it on my 72; it's very easy. You need to replace the drier and all o-rings with the newer R134 style o-rings. I switched to a Sanden compressor for R134 but I'm told the GM ones work. The system must be purged professionally to remove all the R12 oil and freon. The Camaro condenser is fine also. I think it cost me about $60 or so to have the system purged and re-filled with the R134. It works great.

Jody

This is the hearsay in Michigan. Supposedly, the 134A has much smaller molecules than the R12. So small that the 134A will bleed through the lines that came with the R12.
At this point, I know of 7 changeovers from R12 to 134A with no bleed through. The oldest is 2 1/2 years and the newest about 7 months.
Evacuation is critical though. It must be done professionally, not just released to the atmosphere (that's illegal anyway), to avoid contamination as much as possible.

There is a inexpensive kit you can purchase, I have seen them do the conversion on Crank and Chrome their website crankandchrome.com usually lists the products they use on their show..I have actually seen the kit in K-mart, I believe it cost about 40 bucks

Someone had told me about the smaller molecule thing. I wasn't sure if it was true or he was just looking to sell me new hoses too.
Jody, how long ago did you convert your car? Did you replace the hoses? Have you had any trouble with leakage?
Thanks for the help,
Stephen

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67 RS/SS 350 700R4
69 SS clone unfinished
72 454 Weekend Racer

Stephen,

I converted about a year ago. I've had no problems or leakage.

Jody

134A is definately less "efficient" than R12, so you can expect less cooling effect. Also 134A is a smaller molecule than 12, so you can expect more bleeding than you have now, but it could be minimal.

However there are R12 replacement freons which are compatible with R12, but the EPA wants a complete evacuation and recharge with these. One of them is called "Hotshot" by Icor, I forget the names of the others. But anyway these R12 replacements are even more efficient than R12.