has any one tried Maxi12a or Freez12 as a substitute to R12

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124Bill

I would use this sites Search facility. There have been 100s of discussions on the subject.

R-12 purists will chastise you for even mentioning the alternative refrigerant names listed in your opening thread.

Others will tell you Freeze-12 cools better than R-12.

It's a very subjective thing unless you're an R-12 purist.

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Mike Murrell
1991 300-SEL - Model 126
M103 - SOHC
"Fräulein"

Freeze12 really isn't a good alternative for R12 as it's 80% R134. IF your going to go that route, you may as well convert to R134 and be done with it.

I have used R406a in my 280SEL. It is the only drop in replacement that I know of for R12 as it can mix with the oil. It turned my fingers blue while it was in there, but it appears that I had a leak in the system and as a result, it didn't last very long. I guess I need to replace the compressor and 34 year old hoses.

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With best regards

Al

Here is a blurb that I copied from http://www.imperialclub.com/Repair/Air/refit.htm
"Now let's compare R406a or GHG-X4:

They are MORE efficient than 12, yet operate at similar pressures,
so the expansion valve calibration will remain optimal and your
existing condenser and evaporator will function MORE than adequately.

They are completely compatible with R12 type oil, so no system flush
or expensive compressor rebuild.

You still need new hoses, because R12 type hoses are permeable to the
smaller R406a factions' molecules.
Ditto new seals. (New hose-to-hose and component-to-component seals,
you don't have to mess with any compressor or other internal seals). The choice is crystal clear here, isn't it?

Now I have to ask YOU a question:
Why are you converting to anything?
R12 is still around, you know, and anyone who tells you otherwise is
lying or ill-informed. There is plenty of it in the US. There is MORE
than plenty of it in the US. Some garages will tell you that R134a is
the only legal refrigerant. That's wrong. Some will tell you that 134a
"moves more heat" than R12. That's also wrong. Some will tell you that
no flush, rebuild, or anything else is needed when converting to 134a.
That's dangerously wrong. Either use 12, or use 406a, or use GHG-X4.

Any comments from Forum?

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1984 300SD TURBO DIESEL

AC upgrades/improvements
http://www.peachparts.com/shopforum/diesel-discussion/92865-ac-upgrades-improvements.html#post618549

Pictorial on how to fix your A/C system to get 38 degrees at the vent!
http://www.peachparts.com/shopforum/diesel-discussion/126565-pictorial-how-fix-your-c-system-get-38-degrees-vent.html#post912786

R-12 Alternatives.
R-12 alternatives

during the 80,s mercedes started using aluminum evaporators with copper u tubes epoxied in at the ends.at that time they knew that this epoxy would not present a problem when used with r12[large molecules]now here comes 134a and all the exotic derivatives[e.g.fr12,freeze 12 etc]which contain a majority of 134a with something else to carry the mineral oil.all of these refrigerants have common problems when used with r12 systems.firstly just from a performance point of view 134a requires a 50% bigger condenser area just to work and then it will only be 75% as efficient as r12[r12 is an extremely efficient cooler and for many years we were all spoiled because there was no need to apply technology to r12 refrigeration it worked so well]imagine if you will that we still had only 4 cylinder engines but that we used rocket fuel and all you had to do to get more power was push in more fuel.engine technology would still be back in the 50's because no need to make it better. secondly,134a and all it's brothers have very small molecules and when used with r12 hoses it will leech out.now remember the evaporators with the epoxy it will make a hole thru epoxy and then make hole bigger as it leaks out.if your evaporator has been replaced with all copper you have nothing to worry about but replacing it is not a diy job.i am speaking from experience.this happened to me on my 88 300te.david poole european performance dallas texas.

Thanks to all for the input, i think David broke it down scientifically thank you
David. i will stick with R12.

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124Bill

I'm using 100% hardware store propane as my refrigerant. My 89 300SE had already been converted to R134a & Pag oil when I bought it last March, and it cooled the car well enough for a normal, mild summer in northern Illinois. However, I took a trip to St. Louis during one of their famous heat waves last July, and sweltered the whole time.

When I got back I did a lot of research on the subject of alternate refrigerants, including on this forum and decided to give propane a try. It works very well. Far better than R134a in my old Benz system. I don't have anything against R12, except for its cost. As others have pointed out there's still plenty of it around.

First I made up an adapter that would allow me to connect a standard Benz-o-matic 14oz. (the exact amount needed) propane tank to the R134a low side fitting. I had my local indy recover the R134a, then I vacuumed the system down and recharged with the 14oz. of propane as a liquid. Total cost of refrigerant, less that $3.00 from my local Ace hardware.

Works great, even in St. Louis heat waves! And, you gotta love the price.

Btw: The only physical change I made to the car was to install a new dryer. It looked really old, maybe the original, so it was time.

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2000 Mercedes S500
1990 Mercedes 560SEL
1970 Triumph Spitfire

I went thru this a couple years ago.

First, many of the 'R12' replacements are based on propane. Some might wonder about the safety issues of a highly flammable refrigerant.

Second, yes, R12 is available but there are also many selling recovered Rxxx and calling it R12 to make a little extra money.

Third, getting the R12 is the easy part. Most A/C shops have discarded the equipment (gauges, recovery tank, etc.) since there's no business for it any more. So finding someone competent to do R12 is getting harder.

In the end I decided the best thing was to replace the hoses, drier, etc., flush the system and replace with R134 and the proper oil. It didn't seem to get as cold (it shouldn't) but it got cold enough.

Good luck.

I used Enviro-safe refrigerant in my 1979 280CE, its going on 2 years and is working great, no leaks yet. Its much colder than R134 especially in stop and go traffic. It is also a lot easier on the compressor because the head pressures are much lower.

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1985 300TD Turbo Euro-wagon
1979 280CE 225,200 miles
1985 300D Turbo 264,000 miles
1976 240D 190,000 miles
1979 300TD 220,000

GONE but not forgotten
1976 300D 195,300 miles
1983 300D Turbo 175,000 miles

http://i42.photobucket.com/albums/e3...e485-1-2-1.jpg

Oh goody, summer must be coming!

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With best regards

Al

This is certainly a sensible option, but at the end of the day many systems designed for R12 will simply not provide ice-cold air when refitted to work on R134a.

My 1992 Opel Omega Caravan 24v has been retrofitted to R134a and on very hot days (ambient temperatures exceeding 30'C) it takes very long to have the car cool down to a comfortable interior temperature. The system is 100 percent leak-free, with many components having been replaced recently. The conversion was performed by a previous owner - if it were for me to decide, the a/c in this car would still be running on R12, like my 126 does.

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Mateusz
1986 126 500SEL
1986 126 300SE
1992 140 500SE
1996 124 E200T
1999 210 E320T
2017 205 C200T mit Schaltgetriebe!
2010 639 CDI 3.0

Funny thing is that my 6.9 runs R134 and will freeze you out of the car, even on a hot Texas summer.

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With best regards

Al

Was your 116 "properly" converted to R134a? I know on the VW side of things the expansion valve is different between R12 and R134a. It also helps to change the pressure switch so the radiator fan kicks onto high sooner.

-Jason

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1991 350SDL. 230,000 miles (new motor @ 150,000). Blown head gasket

Tesla Model 3. 205,000 miles. Been to 48 states!
Past: A fleet of VW TDIs.... including a V10,a Dieselgate Passat, and 2 ECOdiesels.
2014 Cadillac ELR
2013 Fiat 500E.