Re: R-12 equivalent

I think I may found an answer but I'll post here anyways. It seems that the refrigerants that are illegal are the flammable ones. According to freeze12's website it's not flammable (and also accepted by the epa). Assuming it's legal it meets all my other criteria.

Thanks, it's not like the crap we have to go thru already isn't draconian enough.

No kidding. I've decided to go with the ES-12a, it's legal to purchase too so I wont even be breaking the law. I'm just going to assume that all the R-12 is gone and put in the new stuff (I bought a recharge kit from autorefrigerants.com). Maybe I can find a shop that will pull all the old R-12 out and put a partial vacuum in the system for me for a reasonable price too. Thanks for all the advice everyone.

BZZZT! Enviro-Safe ("ES-12a") is a highly flammable hydrocarbon blend, Federally ILLEGAL to put in an R12 system and illegal at the state-legislation level in Arkansas, Arizona, Connecticut, Florida, Idaho, Iowa, Indiana, Kansas, Louisiana, Maryland, North Dakota, Oklahoma, Texas, Utah, Virginia, Washington, Wisconsin, the District of Columbia and other jurisdictions.

-Stern

Thanks for the warning. I guess for now I'm going to have to go with the polish air conditioning, ie rolling down the windows.

Do you know *why* the EPA doesn't want you putting a flammable refrigerant in your car air conditioner? Because if you have a leak (which seems likely if you're low on refrigerant in the first place), you will have a mixture of combustible gases under your hood looking for an ignition source. How lucky, exactly, do you feel? Would you drive with an under-hood gasoline leak?

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I recently went through this with a 87 RX-7. I opted for using Freeze12. R-12 can not be sold to unlicensed folks like us, though you could attempt to get the license, but then it is still quite expensive and if you have a leak it could become very expensive. Also since you might want to service other newer 134a cars it seems sensible to get the tools you need to do both. Someone else mentioned autofrost and it does seem like a good alternative but we face the same licensing issue with it.

I bought an inexpensive manifold gauge set for R12/R134a from ackits.com ($78). It has 1/4" connectors so you'll probably need a

1/4" to 3/16" adaptor for the high side as I did. I also bought the air operated air pump ($38 ?). My air compressor is light duty, so I had to connect, open gauge, close gauge and disconnect pump to let the compressor repressurize repeatedly to evacuate to near 30 mmHg vacuum. It wasn't difficult, though I expect it sounds like it was. The universal can tap might also be needed.

I bought the Freeze12 from Sherco-Auto.com because they have all the Freeze12 products listed. I chose the qwik-kit that comes with a can tap and Freeze12 port adaptors, though I didn't bother to install them. I also purchased a couple of cans of Freeze12 oil. It's a 4 oz. can with 2 ounces of ester oil and 2 ounces of Freeze12. I also purchased a can of Freeze12 Stop Leak in case my system was leaking badly. So far I don't seem to need it.

If you research refrigerants on the epa website you'll find that Freeze12 is composed of 80% R134a and 20% R??? another refrigerant. (I forget the exact designation, but it's listed on the epa site if you're interested.) The idea is to include this extra refrigerant to carry the mineral oil in an R12 system. Any addtional oil added should be ester oil as found in the Freeze12 Oil charge which will dissolve in the 80% of R134a. With the direct R134a conversion kits the old mineral oil is supposed to sit unused in the system and supposedly will not interfere with its operation. The Freeze12 approach sounds better to me, but I'm no expert.

On recharging I monitored the high and low pressures. I only added 1

12 oz. can of Freeze12 and 1 can of Freeze12 oil. At this point my low side pressure was just slightly exceeding what the service manual calls for using R12 and the high side was at the high sides upper range. It seemed prudent to stop at that point and the system is putting out cold air beautifully. The sight glass shows bubbles, which it shouldn't if charging with R12, but I think it's best to keep the system in the specified pressure range. Long term remains to be seen, but so far I'm very pleased.

Good luck with your RX-7.

Well, that's a legal alternative...when used legally, which you did not do.

What "attempt"? It's a 15-minute, 15-dollar open-book test you can take on the web.

You're supposed to pull and *hold* a 30 in. Hg vacuum, not just reach 30 and say "OK, I'm done". Holding the vacuum on the system for at least 20 minutes boils off the remaining moisture in the system.

Which is illegal. All retrofitted systems *MUST* be equipped with the non-removable service port adaptors and the system *MUST* be labelled as to what refrigerant was used, and how much was installed, in combination with how much of what oil. Bet you didn't bother with that, either. These measures are required so as not to contaminate the supply of reclaimed R12.

R142b

...and the result is that the refrigerant moves even *less* heat than R134a, which in turn moves less heat than R12. Overdesigned systems (there are plenty of these) will work fine on this stuff under low and moderate-demand situations; performance often drops right off under high-demand situations (stuck in traffic on a real hot/humid day).

This is one of the main reasons those little $39 "R134a conversion kits" from the parts store are known as "instant compressor death". What you say here is WRONG! With the direct R134a retrofits, the system must be flushed to remove all the mineral oil, then ester or PAG oil -- compatible with R134a -- must be used. There is no reason to use a hack like Freeze-12 instead of doing the job properly (flush and use R134a).

That is fairly clear. Hope you are the only one who ever works on your A/C system; most shops just say NO when you ask them to work on systems that have been filled with anything other than R12 or R134a. (And don't think that by not using the adaptors and not using the label you'd trick anyone

-- shops have refrigerant detectors.)

Good luck indeed. A halfassed, corner-cutting "retrofit" like yours practically guarantees extensive and expensive repairs down the road.

-Stern

Thanks for the reply, lots of good info in that post. As far as worrying about shops that will service my RX-7 in the future I'm not going to worry. After all if I was going to take it to a shop for service why would I be going for the DIY solution now. Thanks again.

Exactly my view. The laws surrounding R12 must have been lobbied for pretty hard and consumers sure didn't get represented well. Some folks seem hurt and get nasty when they lose another mark, or maybe they're just nasty to begin with. :)

I forgot to mention or ask if you had the service manual that specifies the pressures for your 85 RX7. If not you can find pointers to manuals online at

which is a very useful site for all things RX7.