factory A/C?

[72'BBGMCSGCC]

I have a 72' GMC with Factory A/C which blows cool, and I want to get the system recharged. I called a local guy and he said the R-12 would cost $240 or he could change the system to the134 system. He said it wouldn't be as cold as the R-12 .Is there any advantages or disadvantages with either system?Should I change the system or should I get the system charged with the R-12?. and what all has to be done to change it over?.Is there any type of freon that replaces R-12 , and you don't have to change the system, another guy told me he has a type,but didn't tell me what it was. Thank you everyone. Dave

[mtdave2]

they make several drop in freon types now that are compatible with the r-12 and very cheap. look into one of those. i wouldnt convert untill i had to.

[JimKshortstep4x4]

$240 to add to a system seems a little high, even for R-12. I think R 12 goes for $50-55/lb. and your system only holds 3 1/2 lbs when empty. As I understand your post, your AC works but you want to add to make it colder. I would check with someone else. I only paid $200 a couple of years ago to have my system checked and filled, (it was completely empty as I had put an evaporator in it). I needed the whole charge, (3 1/2 lbs.).

Most AC guys around here recommend the R 134 if you change out, ($3/lb. approximately). The cooling loss is not noticeable according to guys that have had theirs changed to R 134. We still
use the R 12 but are planning to go with R 134 when we do the Burb AC, (front and rear AC) which uses over 6 lbs.

Jim

[dtlilly]

The cheeper R-12 is called FR-12. I use only this for customers with R-12 systems. Many shops try to sell you on the idea that a conversion to R-134. I do not, in fact I steer customers away from converting their system, unless they intend to replace every component. Purging the oil, freon and sometimes stop leak and leak detector fluids from the system leaves some contaminants still present. When you convert to R-134 the compressor which has operated from new with R-12, has a better probability of failure. I also can't get the same crisp cold air blowing from the vents with conversion to R-134. For the most part, there is a deviation of about 10 degrees when you convert. On real hot and humid days, like the period from June to September here in Memphis, you will need to have your air on full blast just to make things tolerable.

[dmurphy68]

I like the ac i have 4/60. if you dont know what i am talking about that is 2windows down and wings open on 60 mph lol sorry just had to say it
Darren

[ozarkhippie]

I converted a old kenworth I had to 134 and it cooled then I had compressor problem and had to recharge. The next time I used freeze 12 and it cooled like I thought it should like r12 did. I also converted a 86 chevy to 134 after having repairs and it didn't seem to cool as much as before. So I think the freeze 12 cools alot more than the 134.