AC freon replacement

radman · 09-27-04, 01:30 PM

Recently purchase '78 vette. The original AC does not work. Prior owner had car largely in storage for several years with a few drives each year. I suspect the R12 freon is gone. Would like to replace with R134 or other product. Some have suggested 401a, 409a or 406a as other possibilities. Once I recover the existing R12, can I then add one of the other products and lubricant? Does anthing else need to be done to the system?

JonM · 09-27-04, 01:47 PM

Check this out...I would suspect O rings and other rubber parts may all need replacing.

http://www.id-usa.com/how_to.asp

radman · 09-27-04, 02:29 PM

JonM
Tried that site, but they don't mention anything about modifing the existing system. I was hoping someone has already tried changing their system to a different coolant.

Grizzly · 09-27-04, 02:52 PM

Quote:

Originally Posted by radman

JonM
Tried that site, but they don't mention anything about modifing the existing system. I was hoping someone has already tried changing their system to a different coolant.

Several years ago changed my 87 Chev pickup to R134 with no other changes. Still works, no leaks.

JonM · 09-27-04, 03:06 PM

Quote:

Originally Posted by radman

JonM
Tried that site, but they don't mention anything about modifing the existing system. I was hoping someone has already tried changing their system to a different coolant.

Did you look at the retrofit vid? http://www.id-usa.com/how_to_retrofit.asp

Bill75 · 09-27-04, 03:57 PM

I believe R134 is about 80% as efficient as R12. I would first have someone fix the problem be it a leak or other problem, then replace the refrigerant with R12, it's still available just bring your checkbook. Your 78 has a lot of glass in the rear, I think others may warn you about converting to R134 that it may not have the ability to keep it cool. There is also the choice of R12A which is a hydrocarbon material, even more efficient that R12. Much lower head pressures so you may not have to replace any components. You might want to look into it. Possible someone on here has tried it and could offer a comment. Attached is a link to the tech info.

Bill

http://www.deepfreezeinc.ca/techinf.htm

radman · 09-27-04, 04:44 PM

JonM:
I can't seem to get the vid to work on my computer. Website problem?

Bill 75:
I like the idea of "Duracool" in my system. I will have to call them to check pricing. I plan to have the system checked for leaks or other problems. I had R12 put a Ford Escort AC several years ago and the price for just the R12 was $150. The system was checked for leaks and one hose was replaced. The cost was $150 for just the R12. Drove the car for one day and blew the high pressure hose off that they replaced. The service shop wanted to charge another $150 for R12 replacement. After a "discussion" with them, they did it for N/C.

G Winter · 09-27-04, 07:10 PM

I have replaced R12 with the 134A a number of times, all with good luck.
some cooled better witht he 134A and some not quite as good but not enough to be concerned about. When you convert you only use 80% as much by wieght as you would with R12. It is best if you can remove most of the exsisting oil in the system. My vette shows low refrigerent on the scanner. I plan on evactuating the system next spring and refilling with 134A . The car that worked preticularly well with the 134A was an 88 pontiac Grand Am with a 4 cyl. Cooled much better than it ever did with the R12 in it.

rw24 · 09-27-04, 07:14 PM

I changed my 1980 over to R134a. With mine though I had to replace the compressor and the accumulator because the system had not been running for a couple of years. One thing you might want to do is get a R134a conversion kit which comes with adapters so that you will be able use quick connect equipment on your AC system and it also comes with freon and oil for the AC system. The kit is available at any automotive store for about $30. Just make sure that all of the R12 freon is gone from the system and that the system is holding a vaccuum good. Other than that you should have no problem changing the system over to R134a. I done everything on my AC myself and had no problem doing it. Sure beat taking it to a garage and having to pay a load of money to have it fixed.

DDLS1 · 09-27-04, 08:25 PM

In 2000, I recovered what little R-12 was left in the system on my 81. Installed 3 pounds of 401A, no other changes or modifications. 3 years and 10k miles later it still was going strong with 38 degree coming out the vents when I sold it in August. There are many options, this one worked, cost $80, and required nothing other than a vacuum pump, recovery tank, and someone to shoot in 3 pounds of freon.