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134 conversion

This topic has been talked to death. Usually every year starting in May. My opinion is that if you're going to convert an R12, the only alternative should be R134a. Avoid Freeze 12, Propane (envirosafe etc) or other blends for the following reasons:
  1. They're usually not better, or worse than R134a
  2. They're blends and therefore leak at different rates
  3. They're in some cases illegal
  4. A shop won't go near your car with their recovery machine if you don't use anything other than R12 or R134a
If you can get R12 and have a tight a/c system, then stick with R12. Even at $40/can, it's cheaper than a conversion. If you have a non functioning system that you're planning to go through, then you have nothing to lose by converting it. Unless you live in a very hot climate or drive a car with marginal a/c systems (like a W126 Mercedes). It will function fine.
 
The car I am considering to buy has been converted to 134. My wife suffers from PAH and cold AC is paramount for her, we live in Miami.
 
550Maranello said:
The car I am considering to buy has been converted to 134. My wife suffers from PAH and cold AC is paramount for her, we live in Miami.
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What year/model car was converted to 134?

You can always convert back to R-12 but it is time consuming and therefore costly.
 
My SEC was professionally converted to 134 right before I bought it in 2002. Never worked well at all. I converted it back to R-12 in Texas back in about 2012 and it was back to blowing ice cold air.

DO NOT CONVERT A CAR DESIGNED FOR R-12 TO 134a. YOU WILL REGRET IT IN HOT WEATHER. Just have it revamped and filled with the more efficient R-12 the system was designed for. And as said do not use substitutes. Only genuine R-12.
 
550Maranello said:
1990 560SEC
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If you love the car and need ice cold AC, have it converted back to R12. As noted above, you may not be happy with the performance of the conversion on the hottest days of summer. Might be ok in spring & fall though.

:spend:
 
Agree R12 for the 126 chassis.

As with Gerry, I wish I did not have 134a when my compressor died but I did not know any better when I bought the car over 12 years ago. I have no problem with the Houston heat and 134 blowing "cool" eventually as I do not drive much to often during the summer in the C126. I have the tint that is clear on the windscreen and the glass sunroof that prevents the heat from the UV rays from completely penetrating the car. As such, the AC does much better and I still get in the shade as much as I can to park. That being said, it is not efficient. I have torn down and replaced the interior under-dash AC system, expansion valve since the conversion took place in 2010. So then since my systems are relatively new, I am cooler than I was and I obviously no longer have freon leaks. I used R134 from name brands, and junk brands on the cheap.

I have used Envirosafe after evacuating the system. From the solitary personal experience, my car - in my circumstance has better a/c performance with the Envirosafe formula. I do not endorse it, and it makes no difference to me either way. The temps feel cooler for me and that may just be due to the simultaneous use of today's heat protection tints on the car that is 199 with a lot of glass covered areas in humid hot Houston. If it is 80% humid and 92F outside, and I get in the car, it is warm but not instantly sweat producing and 5-10 degrees matter heat wise. It takes less time to cool the car down when it is not 25-30 degree hotter than the air temps. BUT - it still takes non-stop driving to get the air cool enough in your face and the hot air out of the car with windows open.

Accordingly, $200 per can of R12, 2-3x PER YEAR ON A LEAKY SYSTEM IS BETTER THAN 134 of any type. If I did it all over again, I would convert to R12, spend the purchase price of my car ($2,500 in 2010) and acquire as much contraband R12 I could get from Mexico. If you can find a shop that will evacuate the r134, change out all the service ports/O rings, dryer, switch, veritcal hose from the condenser and give you R12 with a warranty....I would jump on that.
 
gerryvz said:
DO NOT CONVERT A CAR DESIGNED FOR R-12 TO 134a. YOU WILL REGRET IT IN HOT WEATHER.
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Most of my W126 didn't do well with R134a. Exception was the white 91 560SEL which worked fine hence why I think there's more to it.

My 84 Rolls Royce corniche blows snowballs with R134a. Using R12 on that car would be a waste of money.
 
alabbasi said:
Most of my W126 didn't do well with R134a. Exception was the white 91 560SEL which worked fine hence why I think there's more to it.
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The system components changed slightly in design between factory R12 and factory R134a, on the W124 chassis. I believe the 126 production ceased before factory R134a system were produced.

124's with factory R12 *or* factory R134a both cool very well, but a converted R12 system does not do well in high ambient temps. I'm pretty sure some component had increased capacity (compressor? condenser? definitely the electric fans) to allow factory R134a to cool better.

:grouphug:
 
gsxr said:
124's with factory R12 *or* factory R134a both cool very well, but a converted R12 system does not do well in high ambient temps. I'm pretty sure some component had increased capacity (compressor? condenser? definitely the electric fans) to allow factory R134a to cool better.
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My opinion is that a lot of this has to do with the way it was converted rather than the refrigerant itself. These cars (W126) went through a period where they were worth what they weighed in scrap, and a lot of them were neglected. I expect that many of the conversions simply involved those kits that came 3 cans of R134a, mixed with leak sealer and ester oil which they would dump into the system, probably without evacuating the old refrigerant or flushing the oil. When it leaks out, more gets dumped in with more leak sealer and oil and before you know it, the system barely functions.

I once vacuumed a system and sucked out a ridiculous amount of oil, another time a guy I knew came by the hobby shop to flush a condenser for a 300SD and we had to use a blow gun with 150psi of air to blow out all the sludge that was in there. It was nasty.

Aside from the refrigerant, there are many other reasons for a W126 system to not function well. Vacuum pods for the vents, failing mono valves and electric fans that can't keep up at idle are to name but a few. The newest W126 is over 30 years old now, unless it's a one owner car and you happen to know the owner who's a nut about maintaining a car, I would expect that the has some stories to tell.

I don't count on mechanics to do it right, even if they're specialists or dealers.
 
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In USA most all Mercedes models had R-134a as of 1992 USA model year. Not sure about outside USA. Other mfr's may have switched in 93.

R-12 wasn't made illegal at the time, but you had to be certified to purchase it, and I think production of R-12 stopped circa 1996?

:scratchchin:
 
I still have two full jugs of R12 and about 5 full jugs of R134 which I bought after I started seeing prices creep up. I was buying R134a jugs at $100 for 30lbs. Last time I checked Worldpac, it was closer to $400.
 
alabbasi said:
I still have two full jugs of R12 and about 5 full jugs of R134 which I bought after I started seeing prices creep up. I was buying R134a jugs at $100 for 30lbs. Last time I checked Worldpac, it was closer to $400.
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OUCH! Has R-134a really gone up to the $400 range? I bought a tank a few years ago for ~$160 at O'Reilly but haven't paid much attention since then. It was genuine USA stuff too, Chemours branded. Apparently I should have bought more.

:runexe:
 
I just checked it again now and the prices have gone down a bit to $289 + tax. Likely due to it coming up towards the end of season. By April of next year, I bet money it's going to be back up to $400 or more.

Autozone has it for $369 right now so WP is a better deal if you have an account.


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