69ishHoliday

My Air Conditioning is currently non-working and I'm leaning toward replacing the compressor with the 134 version. In talking with tech at Summit I'm told that there are three different oil weights to choose from (40,100,&150) and they weren't able to tell me which I should use. Any input from a member that's converted their car to 134 would be appreciated. Thanks, - Steven

MDchanic

To convert to 134, you need to change the receiver, the condenser, and the O-rings, as well as recalibrate the POA valve.
It is wise to change the hoses as well, although many have gotten away without doing it.

I forget which oil goes with 134, but I believe it's PAG. Doesn't matter - a quick internet search will tell you that one small piece of information.

Why not just stick with R-12?

- Eric

69ishHoliday

Thank you Eric,
The AC hasn't been working for about ten years and the cost per pound is so expensive. If I knew the freon I put in wasn't going to just leak down I'd go that way for sure. It is something to consider though. - Steven

MDchanic

You're welcome.
R-12 is getting cheaper, as fewer and fewer cars can use it.
I bought several of the small cans at a flea market recently for $10 a can, while the R-134 goes for $14 a can nowadays.

Considering the cost of the parts needed to switch (and if you don't use them you'll get "eh." cooling and won't be happy), it may be cheaper to have the system serviced as-is with R-12.

Both ways will work fine if done correctly, though.

- Eric

jensenracing77

Just be sure it is leak checked with nitrogen before you charge it with the R-12. I have even left 200PSI of nitrogen pressure on a system for a week and checked it again to be sure it still had 200PSI in it. Just be sure you DO NOT try to run the system with the nitrogen pressure in it.

69ishHoliday

Good information from both of you! The local AC automotive shop I spoke with was telling me $130 per can for R12. I think I'll look around for some on my own. I will make sure the shop I end up using does a thorough pressure check. Thanks, - Steven

jensenracing77

A shop will have a high price on the R-12. Like Eric said, you can find it now and then from individuals for much less. Because of my certification, I can not sell you any R-12 but I know an individual that has 3 cans of R-12. He wants $25 per can. I think two cans are 14oz and the other can is 12oz. I can hook you up with him if you are interested.

jag1886

You also have to flush the entire system of get the old oil out of everything. R-12 and R134 oil are not compatible.

MDchanic

True, but ester oils are compatible with both mineral oils (R-12) and PAG oils (R-134), if need be.

- Eric

68442Convertible

That is exactly what I have been reading regarding ester oil (POE or polyol ester oil). Some call it retrofit oil. Isn't that what you are suppose to use when converting from R12 to R134a?