Replacement for R-12 coolant (not R-134a) ?

The two oils do not like each other very much. When I went back to 12 from 134 I pulled off everything I could pull off and let it drip empty all weekend. That was a bit costly which is why I don't know how pissed I need to be now that I found out that my request for R12 again resulted in the Freeze 12. If Freeze 12 is nothing more than 134 in disguise - I am right back to square one.

That's why I need someone who knows to tell me If I can simply evacuate my system of the Freeze and simply load it with R12 without the oil mix problem and having to pull everything off again and let it drip dry empty.

I guess my basic question is this; Is Freeze 12 oil and R12 oil compatable?

 

Unfortunately, it said YEARS ago. It was before the ban was put into place. Sam's discontinued the 12 ounce cans, but stocked the 30# cylinders. I thought it would be a good investment at the time. Should have bought a truck load.

 

Just redid my 328 system with DuraCool products. Added the Oil Chill which lubricates and quiets the system, and the Seal Quick to take care of any leaks, and filled it with Dura Cool 12A. Mail order was a breeze and had the mechanic put it all in. I'm in Florida and my nipples are hard it's so cold.

 

Why don't you disconnect the compressor and flush the rest of the system
yourself. I've done it on a couple of cars. Drain the compressor and then use one of the new oils that's compatible with both forms of refrigerant.

I'd hand clean on a bench the expansion valve if you have one.

It can be kind of a pain separating all the various portions of the system and flushing them individually but if you're patient and methodical it works.

Blowing a lot of compressed air through the system is not a good idea though.
Have your AC tech flush it with nitrogen before evacuating and charging it.
Oh yeah, toss the receiver drier.

Bob S.

 

Hey Paul, are you sure this is the way it happened? Some time ago, I ran across this article, and sonded pretty legit.....check it out and pls comment:http://www.imcool.com/articles/aircondition/refrigerant_history.htm

Or anyone else for that matter.

 

Sorry for delay in reply, Tommy. First, I am not an expert, like most, I like to plink around. I did do 3 systems though, and learnt a little. Re your question, I know that if you have Classic R12 WITH classic mineral oil, one must get it ALL out, before you convert to R134a, or residues in min oil will create these acids we've been discussing here.

And , yeah, you're right, this freeze 12 which is 80% R134a lends to the same problem in converting, to me. I have a friend who I can call upon for this advice, but not til monday. He is a pro. If you are not planning to do this this wkend, I will try to contact him Mon and get back to you.

You're doing this right....take your time, as I did on my 3 cars, and better chances for things to go well. Man, I wish someone here was an expert in AC.....do we have no one???

 

Dr T if you had used the freeze 12 then it has compatible minerial oil in it and it does NOT need to be evacuated. The newer oils are cross compatible with 134A or R12 so there is not a problem. This was done because of the large amount of conversions that started to take place back in 1995 when R12 was stopped. If you look at the bottle that you get the oil in it states it can be used for either. So no need to drain or flush the system. Just change the receiver drier and pump down the system for a few hours and you should be ready to refil . Enjoy the ride

 

thank you thank you thank you

 

This, basically, isn't going to happen. It won't happen because R134a systems can be designed to work well. Actually, they can work very well. We will be stuck in R134a land for many years to come unless some wacky regulations get passed, in which case we will be using CO2 systems for their higher overall efficiency.

Conversions, on the other hand, are another issue entirely.

If the condenser capacity is sufficient, then all the technical hurdles are easily overcome for a conversion from R12 to R134a. A complete flush, new oil, seals compatible with the oil, changing the fixed orifice or adjusting the thermal expansion valve, and a desicant package compatible with R134 and oil are all that is needed. Add fitting adapters and a high pressure cutoff switch if the conversion is done commercially. Done. It will work well, and has been done successfully in many cars. (Also note that many potentially successful conversions are not successful because some of the steps were skipped.)

If the condenser capacity in NOT sufficient, then it is an ugly mess. R134a condenser pressures are higher for a given temperature (or stated in reverse, higher pressures are necessary to get the temperature up in the existing condenser to reject enough heat to condense the working gas.) The higher pressures may cause the compressor to cut out (if a HPCO switch is in the system) and likely cause early compressor failure. Condenser capacity can be increased by installing a bigger or more efficient condenser, or increasing airflow (typically a big problem at low vehicle speeds) by using a honkin' big electric fan. This increases the conversion cost. Likely a lot of horror stories come from this situation where people will not spend for a minimal conversion, let alone the additional cost of modifying condenser capacity. A $30 store kit will not a good conversion make.

I converted my early Explorer to R134a when I replaced a leaking hose. It's condenser capacity was not sufficient. It worked great at speed, and at idle to about 100F ambient. I mean it worked well (like 40F vent temperatures.) But if ambient got above 100F, and the engine was above idle, and the the vehicle speed was low (like every time I accelerate from a stop) then the airflow through the condenser was not sufficient to condense all the R134a gas to a liquid, and the high side pressure would climb until the HPCO (I had installed one) cut the compressor out. I did not feel that things would last, so I converted it back to R12. Yes, it was a pain flushing everything again, and replacing the dessicant again, but it is reliable. I looked into adding a booster fan, but there was a transmission cooler in front of the condenser that made this impractical. But had I really wanted too (i.e. if I was out of R12,) I could have converted entirely from the mechanical fan behind the radiator to an all electric fan, and the conversion would have been successful.

Anyway, to anyone interested in converting, I would recommend only R134a (because you can get it serviced easily) and doing it completely correctly. If necessary, add condenser capacity with a better condenser or an electric booster fan. It will work.

Lots of good info at this Forum: http://www.autoacforum.com/categories.cfm?catid=20

 

Are you referring to Ester oil? Then Yeah, just as long as it is Ester, which is compatible with both.

 

Just a tech comment.....I think you mean compatible ester oils, not mineral oils, as mineral oils are NOT compatible with other refrigerants other than old R12. Mineral oil has traces of Chlorine, which will form the acids that cause Black Death.

Tommy, does your system have ester in it? the guy who put it in should know.

 

That is NOT the 'Black Death'. Black death is the result of teflon compressor ring material being ground into a powder, mixing with coolant & oil, & being distributed throughout the system. It bonds to the system's surfaces, almost like powdercoating & clogs things up. It's extremely difficult to remove, even with special flushing equipment.

For details see:

http://www.aircondition.com/

This site is a great resource, it's the Fchat of A/C forums, with archives going back to 1997 or so.

Refrigerants & water do form an organic acid that will destroy a system. I've never heard of R12 & R134a cross reacting, however, a good 30+ minuite evacuation will remove either of them.

A 2nd problem is that the mineral oil used with R12 systems is soluble in R12 & thus the R12 flowing throughout the system carries the lubricating mineral oil with it.

Mineral oil is NOT very soluble in R134a, thus as much of it as possible needs to be replaced with a R134a soluble oil. If only a small % of R134a compatible oil is added instead of replacing most of the mineral oil, that small % or compatible oil is all that gets circulated throughout the system by R134a, hence takes a real beating & is prone to premature breakdown, leading to rapid wear of moving parts inside the system.

 

Right, Verell, its not so much the actual refrigerants of R12 and R134, as it is their lubricants/residues that cause this problem. You cant have mineral oil residues from R12 mix with R134 (sorry, shoulda explained that). Nevertheless, cross contamination of these refrigerants are not a good idea, and one can find these articles on the web easily.

Now, that article is interesting, but one can find other articles explaining it (Black Death) with a different twist, with other than the "teflon bits" as being the main culprit.....http://www.ackits.com/merchant.mvc?Screen=CTGY&Store_Code=01&Category_Code=BlackDeath

Keep in mind that some articles can be skewed to favor whatever that sponsor is selling. It is a view that Black Death is primarily not so much the teflon coated gunk, but solder flux from condenser and aluminum shavings gooed up which first harden in the condensor. Then as the system is charged and running, over some time it will clog up the orifice tube, clogging further, and causing the compressor, of course, to fail. You cant then clean the condenser, only to replace it and other components. And they refer to it as "metal", not teflon, although, I believe that your teflon article is v legit and a serious issue.

More research? The most credible rersearch? How much time do we have?....

 

Dr Tommy,
As promised, I called my bud the pro ac guy, here in St Pete, and he said this: Typically, one puts in Freeze 12, considered a "drop in" gas with the existing mineral oil. Assuming that, you can go back to R12 once you evacuate the Freeze 12 out, without having to worry about the oil, as it is the min oil that is compatable with the R12.

What oil did you put in with the Freeze 12? I believe you said you drained the system all out?? Anyway, man, I wish you the best to sort it out....

 

Now I've read in several places "black death" refers to the black ooze that that the compressor seals that were designed to work with R12 turn into when exposed to the 134 oils. oh well, it's all bad......

 

I'll have to look into this to find out. It has been about a year and a half. I really appreciate your help.

 

If you want to purchase the smaller cans of Freon 12,take Epa test 609.

Just another 25 bucks and its an open book test.

The test is taken over the net, I took the test with a bad hangover..

http://www.epatest.com/608/

You will see the link for 609 on the link...

HTH

 

Sure thing, doc....In conclusion, just remember what I try to live by in ac: if possible, when converting or converting back, flush the smitherines out of the system, then start over with the right oils/gasses. You will not go wrong.

AND plan on fixing something again in, say, 5 yrs or so. And the hell with what the actual chemistry of black death is. I would'nt be any happier!!

Let us know what happens, got it?