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  #1  
Old 05-17-2002, 10:11 AM
tcraney
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R12 Refigerant replacements Freeze 12?

My Auto: 88 300TE
Subject: R12 Replacement
After some analysis I have found some R12 Replacment Refigerant/Lubricant combinations ie: Mc Cool, Freezone, Freeze 12 have mixed reliability with the rubber seals ie: some work well with Nitrile others work well with Neoprene (for more information on this do a search on http://www.santech.com/Testing.htm

Only R12 and R134 have complete reliability.

Anyone with experience here?

Thanks Tom Craney
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  #2  
Old 05-17-2002, 11:17 AM
LarryBible
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At first thought you may not be worried about propane as a refrigerant, after all, it's sealed up in the system. But, what happens if a compressor siezes making a spark? Answer: the car turns into a bomb.

Did you see the picture of the bus in Israel about a month or so ago that was taken out by the suicide bomber? The top was blown completely out of it. That's what your car would look like if your compressor siezed.

So, I ask you, do you feel lucky?

Please don't take this approach.

If you insist on not using R12, and I understand the problem, VERY expensive, take the capacity loss and PROPERLY convert it to R134.

Good luck,
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  #3  
Old 05-17-2002, 01:11 PM
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Not all of these are hydrocarbons, some of the more interesting alternatives may be worth taking a look at.

The big problem with R134a - other than the fact that it doesn't cool as well as R12 - is it's not compatible with the mineral oil used to lubricate the compressor in R12 systems. By compatible I mean it is not miscible - it does not carry the oil through the system and return it to the compressor. Just filling an R12 system with R134a will cause the compressor to die in short order.

Hence along came some of these blends. Many are comprised of 80% or more R134a, with another component added in an attempt to move the mineral oil through the system. I believe Freeze-12 falls into this category, among others.

I'm personally running Autofrost - R406a - in my 124 wagon. I don't have enough time on it yet to say it won't break with any authority, but it sure does cool great. On the highway I'm seeing a 37 degree drop from ambient, which is very good. It's almost too darn cold, which is not a complaint one hears very often about the 124 series. Anyways, R406a merits a 'nonflammable' rating. It's a blend of three components: R-22, R142b, & 4% isobutane. The latter helps it move the refrigerant oil through the system. So I have ~1fl ounce of isobutane in my a/c system. Consdering it is also filled with 8 ounces of lubricating oil, I'm not gonna worry about it too much. The cost is ~$9/can, so it's a lot cheaper than R-12, though actually more expensive than R-134a.

Given all the glass area of a wagon, and that I live in Texas, I'd sell the wagon before converting it to R134a. It just doesn't work well enough.
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  #4  
Old 05-17-2002, 01:59 PM
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jcyuhn

What year and miles on your wagon? I have a '91 300E that is in need of a recharge. I went to the Autofrost site (http://www.autofrost.com/) and there is some discussion about seal compatibility.
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  #5  
Old 05-17-2002, 04:54 PM
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Mine's an '87 with about 120K miles on it. I should point out the reason I am running Autofrost is because the previous compressor failed in a nasty way and vented the last of my R12. I had to disassemble & flush the entire system. While apart, I changed every o-ring, so using neoprene as recommended was not an issue. What remains to be seen is how well the compressor shaft seal holds up. Since I didn't want to risk trashing an expensive new or rebuilt compressor, I just got one from the boneyard. It's an original, unrebuilt Nippondenso off a 1987 190D. I just cleaned it up, adjusted the clutch gap down to specification, replaced the o-rings, and it's been running great ever since. High & low side pressures are comfortably within specifications, cooling is great; we'll see about durability.
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  #6  
Old 05-17-2002, 05:00 PM
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This topic has come up many times, just ask the techs who work on these cars for a living.Freeze 12 is junk and all those other (cheap) refigerants well thats what they are cheap.Best thing to say here is if you are not using r12 or r134a dont expect the system to last.
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  #7  
Old 05-21-2002, 10:55 PM
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My first 300SDL was converted to 134a and it cooled just as well as it did with a proper charge of R-12.
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  #8  
Old 05-22-2002, 05:42 PM
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Flush it?!?

What do you use to flush the lines?
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  #9  
Old 05-22-2002, 09:50 PM
Jackd
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4 years ago, an A/C hose developped a leak on my old 1978 Corvette , which was on R-12.
My mechanic did not have any R12 in stock so he proposed a switch to R134. I agreed.
He replaced the leaking hose, drained the system completely, installed the inlet valves adaptor and simply put R134 in.
My A/C has run perfectly since then. No compressor problem, still have the same cooling capacity as with the R12. And no expensive conversion neither.
The hose had to be replaced anyway, the valves adaptors cost about $5.00.
True, I did not add too many miles since that repair (maybe 10,000mi), but again, no problem so far.
maybe it can be done that easy on a Merc.
JackD
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  #10  
Old 05-23-2002, 12:11 AM
Mike Murrell's Avatar
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Freeze-12 is 80% R134A and 20% R142B. Freeze-12 requires special adapters to install...surprised???

This stuff sells for about $12 a can. R134A is about 1/3 to 1/2 of that.

The name Freeze-12 is VERY misleading. You're led to believe that its' an R-12 replacement. If so, how come 80% of it is R134A?

Get a 609 certification and buy your own R-12.
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  #11  
Old 05-24-2002, 11:11 PM
nnbc
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Freon

Change over to 134a it is easyer and more convienent and it is available anywhere. When 134a first came out this was difficult now with the ether oil that is sold whereever you buy 134 it is simple.

You will need to change the shreader valve to a 134 coupling after the system has been properly drained of R12. (Be sure to remove the old shrerader valve.) Vacummn the system, the first can will be the ether oil, then followed with 134. Be certain to only filll it to 80% capacity of the R12.

Enjoy cooling days.

NNBC
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  #12  
Old 05-27-2002, 01:47 PM
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edblock,

I installed new compressor,clutch, lines, expansion valve, rec. and red switch = = had an ac shop flush and refill w/134A.

Sorry for the delay in response = = haven't been here since posting.
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  #13  
Old 05-28-2002, 01:55 AM
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r-12 is 49.99 per lb. At Texaco in Austin texas
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  #14  
Old 06-04-2002, 04:46 PM
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For those of you who have converted from R12, what is your general feeling. How is the cooling? Is it worth it?
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  #15  
Old 06-04-2002, 05:09 PM
LarryBible
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haasman,

The biggest drawback to r134 is lack of cooling capacity. I would think that this would not be a big issue in the bay area. In Texas, believe me, it's an issue.

Good luck,
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