cspangg

Has anyone did the switch to R-134? I fixed my leak but R-12 is way to expensive compared to 134. Is change the compressor oil really all I have to do and then add 134. I'm getting conflicting stories and do you have to drop the COMPRESSOR to change out the oil?

internetautomar

iTrader: (30)

change fittings
suck it dry
refill with oil and "Freon"
done

cspangg

when you say suck it dry, do you mean the compressor?

Greeny

iTrader: (43)

Lots-o-good reading here..

http://forums.maxima.org/showthread.php?t=320081

internetautomar

iTrader: (30)

no, I mean the whole system.

gapboi210

I love my R-12. It's still ice cold.

mtcookson

iTrader: (2)

To do the conversion perfectly so that its very reliable... you have to replace just about every part in the whole system. Last I heard it would cost nearly $1,500 to do it "the right way". Reason being is the chlorides in the R12 and similar refrigerants do not mix with the PAG oil at all. It causes the PAG oil to rapidly break down and will likely cause your compressor to die. See more about that here: http://www.autofrost.com/hotshot/index.html

The best R12 replacement I've found so far is Autofrost R406A. It mixes perfectly with the R12 mineral oil and is actually slightly more efficient, I believe around 10% (but that equates to about 2-3 degrees I believe). The only downside to that stuff is you still have to have a license to get it, but you might be able to talk a shop into getting some for you. It should be quite a bit cheaper than R12 and is easily the best replacement out there.

The next best route that I've seen is ICOR's Hot Shot R414B. They claim you don't have to change the oil... but you do. Once you change the oil it should work pretty good. The problem with the Hot Shot is it doesn't mix well with the standard mineral oil which can potentially starve your compressor of oil and cause it to fail. I believe you have to use an alkylbenzene oil with the Hot Shot for it work properly... but personally I'd just go with the Autofrost to stay away from all of those headaches. Read about oil compatibility here: http://www.autofrost.com/oil/index.html

What I like about the Autofrost is not only does it seem like its good, they prove that its good like with the links I posted above. They give you all of the evidence showing the differences and layout everything in front of you so that you can see what really works and what doesn't. The other guys, like ICOR, go off and claim that you don't have to change the oil or anything and you do... if you don't, you will run the risk of killing your compressor. Here's the link to the Autofrost site and they have a link there to the place you can buy it from (with the proper license). http://www.autofrost.com/frmain.html I believe my uncle has the license to buy refrigerants so I'm going to buy some of that stuff very soon and put them in all of my cars that need a recharge.

One thing I almost about forgot about, there's a slight chance you'll have to change the rubber hoses. Most of the alternatives have what they call "small molecules" and can leak out of non-barrier hoses. I believe barrier hoses were introduced in the early 90's so there's a chance our cars have them, but you'll have to double check. If our cars don't have them, I'd go ahead and replace the hoses with the barrier hose and while you have all that apart replace the seals as well just to be on the safe side. Don't let this deter you from getting the Autofrost though... the R134 is the same way and you'd have to get the barrier hoses for it as well. I believe you do also need to change the fittings to legally convert it. I believe they sell all the fittings you need on the site that sells the Autofrost.

internetautomar

iTrader: (30)

Mark - you don't have to do all that. I've converted several cars myself and the shop has converted several DOZEN cars with nothing more than retrofiting and vacuuming before recharge.
yes the newer refrigerants are a smaller molecule (that's what makes them "safer")

ALL A/C hoses are a "barrier" hose the difference is in burst pressure. 134A is designed to run at a higher pressure than 12 so has higher pressure hoses.
Even when 134 was first approved for automotive use the only thing that was required to be done on a retrofit was to change the fittings, oil, and ALL the seals. But the EPA dropped that requirement YEARS ago because it was BS.

Mark, I'm not picking on you personally, just trying to clear the air on what needs to be done for a retrofit.

mtcookson

iTrader: (2)

Just double checked on this, the barrier hose was introduced along side the R134. Its basically a hose within a hose that reduces the possibility of the refrigerant leaking through.

I totally agree that you can get by without changing everything around and it will work, but I would not expect it to work for very long. Someone had the Z I have now converted to R134 and it was decent at best. I definitely want to try recovering some of the PAG oil and see if what that site says is true.

Regardless, I'm definitely converting it back to something better like the Autofrost because I like it cold in the summer.


Double checked and looks like I was wrong on the temperature drop for the Autofrost. It can actually produce 3 to 10 degrees colder temps than the R12.

todamax

iTrader: (6)

+1, so is mine. Too bad I only use it 3-4 times a year.