OT: Auto AC R12 - R134A conversions - anyone done one?
 

Here's the deal - my 1992 Dodge pickup's AC is no longer blowing cold air. Compressor engages, I can tell a slight temp difference between high/low sides, but no cool air. Truck has 160K+ on it, and chances are that I will be getting a newer and larger truck within the next year or so.

Probably a slow leak somewhere, and the compressor has been making some noise (sounds like bearing noise) for several years. I talked to some local mechanics, did searches on the web, etc. - the general opinion is that you need to completely discharge the system of all R12 and throughly flush all lines and components to remove the R-12 mineral based oil, because it is not compatible with the R134a. Apparently the 134A uses an esther based synthetic oil.

However, my web search turned up quite a few people who obtained satisfactory results using the over-the-counter conversion kits sold at Autozone, Pep Boys, etc., for around $40. The particular kit that I looked at is made by a company called Interdynamics, and consists of a couple cans of R134a, esther based oil, hose/gauge kit, and fittings to retrofit the fill valves. The kit says to simply vacuum out all of the old R12 - it does not mention anything about purging the lines of the R-12 oil.

Has anyone tried one of these, and what kind of results did you get. How long ago did you do it? My thoughts are that I am getting rid of this truck anyway, and I am hesitant to invest $600 + to have it professionally done if I can get by for another summer or two doing it the "cheap" way. (I know, cheap might translate to expensive down the road, but hopefully I won't have the truck then, and the compressor might be on its way out anyway.)

Anyone with experience in this area, please chime in.

All you need is new green seals for all the connections. One new style orifice for the dryer thats it.
Cost you about 30$

Baja27, thanks for the reply. I have been told that it is not necessary to change the expansion valve orifice on the Dodge - just the Fords.

What model vehicle did you convert? Did you have to flush the lines? How long has it been going, and did you notice any decrease in performance (not that this matters - at this point ANY cool air would be an impreovement! :rolleyes: )

Thanks for the help!

I have been doing this since 1996. There is a product called FRIGC FR12. It was distributed through Pennzoil until they were bought out by Quaker State. Try to find this product locally. It will cool 30% faster and colder then 134a. It is NOT a flammable product, It does not contain propane or Butane. It does not contain the damaging r22. This is by far your best alternative! It is compatable will all oils as well as desiants in the driers. I promise you will be very happy. R134A has a much higher head pressure and can blow out your old condensor or eveaporator. Frigic FR12 actually runs lower head pressure then R12. The lower the presure the colder the vent temp. The lower presure also puts less stain on your whole system whichis very important in an older vehicle like yours. Good Luck

I agree with RaceLover. The freeze12 or FRIGC 12 works great and requires no alteration or retrofit to your system. It is slightly more expensive than 134a but it can be added to your existing system.

Where do I get it?
 

Where can I purchase the FRIGC-12? Do they sell it by the can, or will I have to buy a large cylinder?

Has anyone tried the R-406A in cars? It is also supposed to be an R-12 replacement. The website claims lower head pressures, and also says that it is compatible with the high viscosity R-12 mineral oils. They claim that the FRIGC-12 has problems mixing with the R-12 oils.

I've done a couple conversions using the kits available at auto stores.all have been successful.main thing is to recharge at 75% of factory r-12 charge.Usee the oil in the kit and as long as your system is in working order you shouldn't have any problems.