R134a conversions

I realize most are still in winter mode, and some are strictly trail rigs and could care less about a/c...But for us sunbelt daily drivers, anybody had any luck with the conversion kits? I know nothing about a/c but used to manage the R12 diy kits ok back in the old days. Mine's an 87 and only had it a couple months and really don't even have a clue if it's already been converted or not. Is there anyway to tell? Thanks for any input, good or bad would like to hear how your luck went with the el cheapo walmart diy conversion kit.

R134a fittings are different than R12 fittings. Also, it should be labeled if it's been swapped (although usually isn't). I run a garage in Phoenix and won't convert customers cars. R12 is still readily available, not that much more expensive, and (the kicker) at least 90% of A/C system will not run near as cold as it was they were running R12. And that's with doing it professionally (i.e. replacing orifice tubes, accumulators/receiver dryers, flushing the system, etc.). Not worth it just to save a couple bucks.

I use freeze12. works great no conversion nessary.

Please enlighten me, I was under the impression R12 was totally off the market. Is it possible to get the diy R12 kit like I used to buy at kmart?

Take it to a shop. Have them charge it and check it for leaks.

R12 is no longer legal to manufacture, current stocks of R12 are still legal for sale. Its illegal to release refrigerant into the air, it must be sent to a recycling facility, and R12, as well R134a, is an extremely stable chemical that last for many many years and will NOT breakdown. So R12 will be available for years, the current stockpile being recycled as much as possible.

R12 should become more expensive as stock eventually depletes, i.e. supply falls behind demand. BUT, the last R12 vehicles have pretty much reached the end of their lives and have started to head to the junkyard. So the shrinking demand may have come in line with the shrinking supply and the price has come down.

R-134a is slightly less effective than R12, but the important factor is, R-134a condenses at a higher pressure/temperature and evaporates at a lower pressure/temp. This means a R-134a system needs a bigger condenser with more air flow, a slightly stronger compressor and a smaller evaporator compared to an R-12 system.

That is why conversions often don't work as well, the R-12 system has too small a condenser to effectively condense the R-134a and the pump being slightly weaker than needed only makes things worse in this case.

Some vehicles had overkill R-12 systems, bigger condensers and compressors than really needed, these do make for great conversions and work very well with R-134a. Ford Big RWD cars and many Pick-Up trucks come to mind as R-134a conversion working well, because they had these features in their R-12 systems. There info website somewhere on the web, that people have documented how well the R-134a conversions go, thus you can look up your vehicle and see what are the likely results of converting to R-134a. Do a google search.

Also throw in problems with compatibility with different oils and refrigerants, high pressures and smaller R-134a molecues causing leaks from diffusion, if I was a Professional Garage, I wouldn't do the conversion either. Just too many things to go wrong and have to re-do the work.

Like recommended, I would look into R-12 before doing the conversion, your way more likely to have less trouble and probably less cost with R-12 in a R-12 system than converting to R-134a.

I converted an old Mini-Van to R-134a, wish I had looked up the table and saw what kind of candidate this vehicle was for conversion, its a poor one. It easily cost me far more to do the conversion, and fixing the resulting problems then it would have to just pay for the R-12 servicing at the time (1999, when R12 was still in pretty high demand). The AC barely ran cool after the conversion, it was about worthless.

Just use this and dont look back. I've been using it since they took r12 off the market. No problems at all and real cold!!!http://www.freeze12.com/

UncleBud said:

Please enlighten me, I was under the impression R12 was totally off the market. Is it possible to get the diy R12 kit like I used to buy at kmart?

Click to expand...

No!

To purchase R-12 you need a license or registration now to prove you are a profesional A/C person or business. It is still available to them, but most shops no longer keep it or use it, so they only do conversions. The problem is that few of them have working systems to drain and capture the R-12 anymore. Most of them are using 134-a and 134-a recovery (evacuation) systems, and the 2 are not compatable in a recovery system.

I finally gave in last year and converted both my jeeps to 134-a. Not real hard to do, if you know what you are doing. The 134-a in my jeep does not seem to cool as well as the R-12 did, but I am still working on the conversion in the 87 wagoneer (so it is untested so far, I still need to replace the expansion valve as it pluged up right after replacing all the hoses), and the expansion valve is the old OEM in the 85 pioneer. The 134-a is barely adequite in the front seat of my Jeep, but I live in Houston where it reaches 100 F and 150% (at least it seems like 150%) humidity!

If you do switch to 134-a, get all your hoses and hose fitting seals replaced with the new 134-a compatible material first!!! Also, my front compressor seals went out (leaked) on my 85 shortly (1 year) after switching to 134-a. The older 85-87 seals don't seal 134-a too well, plus they are old, worn, dried out and brittle by now. I replaced that compressor last summer rather than fiddle with the seal replacement, 2006.

Also get the drier replaced along with the hoses!

You can get EPA certification here http://www.macsw.org/xcart/product.php?productid=16134

You can buy R-12 on eBay

I guess I am the exception. I know nothing about Freeze 12 but would never argue about getting a conversion done by professionals or at least attempting to do a proper job myself.

Having said that, I have done two conversions (85 XJ, 85 Buick) changing only the charging ports and am pretty sure my 93 XJ was converted changing only the ports although I cannot swear to this. We also had a 93 Regal that was professionally converted with a new compressor etc. I also live in the nasty East Texas weather as well as spending a fair amount of time in South Louisiana and I can honestly say that we have found no appreciable difference in cooling in the 134a systems compared to R12. Also the leaks in the XJs are not discernibly worse. (The Regal now departed never leaked and the "inherited" LeSabre POJ is long gone.) The 93 needs about one can of 134a a year and the 85 about two.

However, I fear that the 22 year old system in the 85 has finally cratered whether from use of 134a or, probably, just plain age I don't know. And I think I will take the 93 to a professional this year for check and charging before I get it totally crapped up with incorrect amount of oil or sludge or whatnot.

All of this is just my anecdotal experience but UncleBud asked about experience with cheapo conversions and I would say that I am satisfied with mine. Probably just dumb luck but I got four years out of an 18 year old system that probably should have cratered a long time ago.

One other possible caveat; I assume the valve configurations on top of the compressors vary somewhat but on mine the "straight" low pressure port that came with the kit would not fit and allow room for the charging connection. NAPA has an el shaped port for ~$4.00 that will solve this problem.