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In the late 90's and early-mid 2000s, R134A conversions were really common. Generally they would blow luke warm. The same cars from the factory with R12 would freeze you out on a summer day. On thirdgens, I've never been in one converted to 134A that really blew cold. But that's just my experience.
Lots of threads on how to do it 'right'. Some of them the people claiming great success even post vent temps. Read up and judge for yourself if it's right for you. Personally I wouldn't expect much from a thirdgen on 134A.
Works ok for me using 92 condenser and new style ac compressor. The blower fan is lacking in power, but vent temps are 45* or less in 100*+ outside temp conditions.
I tried R134 conversions on one 3rd gen fbody, w/ negative results. Compressor got noisey in a few miles. I've tried it on one other car, w/ weak cooling the result and I bought an '83 Cordoba, that the PO had converted. It only cooled well on the days you didn't really need AC!
My 84 Z and 93 Cadillac were converted to r-134 at shops in NC and Fla. before I got them.
They cool ok. The Caddy is colder because it has less exposed glass area.
My old Fleetwood that was r-12 would freeze you out of the car!
R-12 Freon is still avail. on fleabay and such. There are so called b*stard gasses mixed with propane, butane etc.
that will also work in a r-12 system also sold on fleabay. Extremely flammable tho.
I still have 2 20 lb. tanks of r-12 in the garage.
This is the r-134 conversion warning sticker under the hood in my 84-Z.
My Cadillac has a similar conversion sticker.
BTW: What company and person discovered/invented r-12 under the Freon trade name?
Charles (Boss) Kettering, vice president of General Motors Research Corporation, was seeking a refrigerant replacement that would be colorless, odorless, tasteless, nontoxic, and nonflammable. He assembled a team that included Thomas Midgley, Jr., Albert Leon Henne, and Robert McNary. From 1930 to 1935, they developed dichlorodifluoromethane (CCl2F2 or R12), through Kinetic Chemicals which was a joint venture between DuPont and General Motors.[7]
Two things, the PAG oil used with R134 and the oil used in R12 are not compatible and will turn to a varnish and gum up the system. So to do the conversion you have to fully clean out the system of all R12 and oil. Once the system is fully clean it needs to be fully dry so pull a vacuum for several hours. I ran a converted system years ago and it worked pretty good until my compressor died. I didn't do it right and paid the price. I'm running R134 now but I'm LS swapped so its a hodgepodge of components. It seems to work thus far pretty good, but I replaced every thing with new parts, and I mean every single AC component is new.
The other thing to think about is volumn, too much or too little gas will cause it not to work right.
If your R12 system has a charge at all I would keep it going, do not simply drain and fill our it will kill the system eventually.
I was actually worried that my vent temps are sometimes below freezing with the new system. As pointed out get the 92 style condenser as its design is the same as R134 cars.
152 is a good replacement for r12 in these systems.
The 92 condenser uses a different hard line size I thought, or something different from the 88-91 cars............Might be something to look into if somebody just happens to stumble on this thread in the future.
besides the refrigerant used you would need to replace the oil (should be ester oil for both refrigerants) the filter dryer, and confirm that the compressor is capable of handling the different pressures https://forum.aircondition.com/forum...pressure-chart
My 84 Z and 93 Cadillac were converted to r-134 at shops in NC and Fla. before I got them.
They cool ok. The Caddy is colder because it has less exposed glass area.
My old Fleetwood that was r-12 would freeze you out of the car!
R-12 Freon is still avail. on fleabay and such. There are so called b*stard gasses mixed with propane, butane etc.
that will also work in a r-12 system also sold on fleabay. Extremely flammable tho.
I still have 2 20 lb. tanks of r-12 in the garage.
This is the r-134 conversion warning sticker under the hood in my 84-Z.
My Cadillac has a similar conversion sticker.
BTW: What company and person discovered/invented r-12 under the Freon trade name?
152 is a good replacement for r12 in these systems.
The 92 condenser uses a different hard line size I thought, or something different from the 88-91 cars............Might be something to look into if somebody just happens to stumble on this thread in the future.
So I learned something today, Had no idea there was a such thing as an R12 ban. Thanks Government -.-
My AC Seems to be okay, I also live in Alaska which helps... but if I do ever have to service it or replace the Refridgerant, does this ban mean I will have to have one of these conversions performed? Not a fan of this BS.
I believe it is still legal for professionals (with EPA-certified recovery stations) to sell R12. I have two cousins who are professional mechanics, and I had no problem getting my system recharged two years ago.
The off-the-shelf cans for consumers are now illegal, though.
When converting from R12 to R134a I used a parallel condenser. The stock condenser is a tube and fin style which is less efficient at cooling down R134a. One of the bigger issues with the stock system using R134a is the inability for the stock condenser to cool down the R134a enough. The stock tube and fin style seems to work okay if you live in the northern part of the US but I live in Florida and I need all the help I can get. Its something to consider if your thinking about switching to R134a.
What orifice tube are you guys using in the conversion?
I did last year, replaced the accumulator, seals and orifice tube. Using same compressor from 1989 when I bought it new. It blew pretty cold. Have yet to test this season though. Just purge the system from any r12. There is process and you can get the tools pretty cheap from Harbor Freight.
05-20-2019, 12:16 AM
https://forum.aircondition.com/forum...pressure-chart 
