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Re: Any experience with FR12 in C2 A/C systems?
If FR12 means "Freeze 12", read the can. It's 80% R134A! The big problem is that the C2 A/C system regulates the pressure with a "throttle suction valve" 63-66 or a "POA" valve for 67. Both regulate the pressure with mechanical presure control. 134A runs at a higher pressure than R12. Your system will work but not near as good. You will also have to consider that your original hoses are not "vapor barrier" rated hoses. R134A has such a small molecule that it will leak through the old non-barrier rated hoses. It takes a while however it will eventually leak out.
If you want to convert to something other than R12, replace the POA/Throttle suction valve with a replacement tube from "Old Air Producs" or other supplier. This will allow the compresser to "cycle" with a pressure valve set to the type of coolant you choose to use. This is how modern systems regulate pressure. This will not "look" original however the system will WORK MUCH BETTER!
There is some pressure adjustment inside a "POA" valve if you look inside. A quarter turn inside the valve will adjust the pressure "UP" to work better with 134A however I have not had any real success with this "fix". I just replace the valve for a car I drive or bite the bullet and by R12 for a correct restoration car. -
Re: Any experience with FR12 in C2 A/C systems?
FR-12 is diffrent from Freeze 12. FR-12 is a blend made up of 39% HCFC-124, 59% HCF-134a, and 2% Butane. (This per EPA web site at http://www.epa.gov/spdpublc/snap/ref.../macssubs.html)
To me the major problem is getting the system serviced. Most all A/C shops are set up for R12 and 134a. They must have seperate evac equipment for each type of refrigerant that they work with. So cost keeps them from servicing other types of refrigerants. If you do your own work, well and good. But what if you are on the road and need work done on the A/C. Will be very hard to find a shop that has the equipment to work on some off brand refrigerant.
tom...Comment
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Re: Any experience with FR12 in C2 A/C systems?
Tom,
Do you know if the pressure problems Mike spoke of are as much a problem with FR-12? I have been told no modifications need to be done. Is this true?
DarwinComment
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Re: Any experience with FR12 in C2 A/C systems?
Sorry but don't know about the pressures. As far as being told that it can be done with no modifications, well depends upon what is defined as modifications. You will need to replace the o-rings and flush the system. It should then work somewhat with any refregrent. The question is how good? This then takes us back to the pressure issue.
Have seen posts where a system developed a leak, lost the R12, so they just fixed the leak and refilled with one of the WalMart 134a kits. No flush, no o-ring change. They stated that the system worked just fine. Find that hard to believe as 134a is about 10% less effecent then R12. Also wonder how long it worked okay.
Me, I would either go back with R12 (if the system is right it is just a one time expense as it should last for years); or do the flush/0-ring conversion to 134a and make adjustments to the expansion valve to allow for the pressure differences.
tom...Comment
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Re: Any experience with FR12 in C2 A/C systems?
I have not had to do it myself, but according to a co-worker using the Wal-Mart 134a kit it works. He does mechanic work for others and has done his Chev Lumina as well with the 134a kit. He put a new compressor on his Lumina and vacuumed the system down and installed the 134a a few years ago, says still cools fine. What is recommeded by the manufacturer of the kit is available on their web site. www.id-usa.com.Comment
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Re: Any experience with FR12 in C2 A/C systems?
Tom,
A Lumina is a whole different ball game as it is a "modern" car with an accumulator/pressure switch to regulate pressure, not a POA/throttle suction valve like on C2's.
A lot of people use those retro fit kits because they are cheap. Again, they will work however you can (depends on the year car) still have hose issues and you will need to change the O rings and the compressor oil.Comment
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Re: Any experience with FR12 in C2 A/C systems?
Why not just use R-12, that's what the system is designed for. The system holds about 3# or refrigerant. small $$$ in the big picture.Comment
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Re: Any experience with FR12 in C2 A/C systems?
Mike the web page I mentioned says that the hoses and o-rings do not have to be changed and the oil for R12 can stay in the system when converting to 134. The properties of the R12 oil actually protect the hoses. A person would not be wasting a lot of money to just charge the system with 134 and the new oil since it is so readily available off the shelf.Comment
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