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Possible to move AC refrigerant from R134 back to R12?
Changing out the carpet on my 93 FD, I've been working to pull the heater core out... For the life of me, I can't get enough purchase to pull the heater core and clear the coolant pipes through the firewall without also disconnecting the AC.
Of course disconnecting the AC means dealing with removing the refrigerant, and refilling.... It's really unclear what the previous owners did or didn't do, but based on the asymmetric sized quick connects on the AC lines, it looks like the car is currently running R134.
Since I am now looking at a remove & recharge, I was inclined to move back to R12, or I do now need to stick with R134? I believe the o-ring material for either r12 or r134 is the same, and was looking to get these: https://www.autozone.com/cooling-hea...592/703895_0_0
It's a touring with a Denso system (silver dryer).
There are several forum members who can speak more intelligently on this topic, but I will say my piece.
I have R134 in my car (1995s came with it from the factory) and my AC works great, better than the R1234yf in my 2017 Civic. The only time my AC suffers is when at a stand still in extreme heat. I live in South Texas on the Gulf, a few hours from Mexico. Very few places in the US get hotter, so take that for what it is worth. You can look for a sticker under the hood of your car and it will tell you if it was equipped with R12 or R134 if uncertain and on the AC compressor itself. R12 is hard to come by these days and many owners are using computer duster (it is actually a refrigerant, not just compressed air). If it were me I would stick with R134, because I have had great success with it, but I am sure R12 would be slightly better.
I woudl first exhaust all options to remove the heater core with the AC evaporator installed. There are 3 bolts holding the evaporator to the firewall and then it will pull straight back. There should be enough slop in the lines under the hood if you unhook them from their mounts you can move that evaporator box back 2-3 inches or so.
All that said, if you do remove the 134a I would probably go to Dust-Off, R152a, as a replacement. On an R12 system if you charge with 134 you will get AC that is cool but not cold. 152a will cool just as well as R12. But, in the part of the country you are in, you may not need that level of cooling. If your car's AC does well and you are happy with it just stick with 134a. It's cheap and easy to do and really you can have an AC shop do the work if you don't want to fool with it.
Man I love this forum. Dale, Steve, thanks for the advice.
After sleeping on it, I tried again, asking myself, how come everyone else can get enough freedom to pull this but I can't? Turns out that the angle and size of the aftermarket R134 connectors on the AC lines were interfering with the ABS heatshield so that the AC box couldn't slide far enough into the cabin to release the heater core. I pulled the ABS heat shield and loosened the the ABS bracket and got the crazy thing free.
Draining averted, but if I do have to refill in the future, I'll go the R152a route.
There are several forum members who can speak more intelligently on this topic, but I will say my piece.
I have R134 in my car (1995s came with it from the factory) and my AC works great, better than the R1234yf in my 2017 Civic. The only time my AC suffers is when at a stand still in extreme heat. I live in South Texas on the Gulf, a few hours from Mexico. Very few places in the US get hotter, so take that for what it is worth. You can look for a sticker under the hood of your car and it will tell you if it was equipped with R12 or R134 if uncertain and on the AC compressor itself. R12 is hard to come by these days and many owners are using computer duster (it is actually a refrigerant, not just compressed air). If it were me I would stick with R134, because I have had great success with it, but I am sure R12 would be slightly better.
The sad part is, this sticker is not on my car anymore. I wrecked the car and bought a 94 hood that sits on the car now. I just took this picture to get a copy made.
06-19-22, 04:52 PM
