ac conversion from r12 anyone have a kit? - PeachParts Mercedes-Benz Forum

86 300E · #1 08-26-2010, 05:40 AM

anyone have a kit or some experience with it?
diy for it?

Aquaticedge · #2 08-26-2010, 05:52 AM

they sell them all over, but fwiw, stick with R12, it keeps your car cooler and your compressor is designed for it,

#3 08-26-2010, 07:56 AM

R12 is so cheap in today's market, the difference in R12 vs. R134a is not much more than what the kit would cost. If anyone tries to sell you R12 for more than $20 or $25 a pound, tell them to go pound sand.

In addition to the cost issue, statistically R12 systems converted to 134 last about two years before attention of some sort is necessary. If your system was designed for R12, you are MUCH better off with R12. If for some reason you are absolutely bent on using another refrigerant, make it 134 and get ready for the reduced cooling capacity, reduced long term system reliability, and increased long term cost.

NOW, get ready for an onslaught of suggestions and endorsements for every kind of junk refrigerant you can imagine. By this time tomorrow, this thread will be full of them.

Good luck,

gerryvz · #4 08-27-2010, 10:54 PM

Hmmm...waiting for junk refrigerant endorsements. Anyone see any?!?

duxthe1 · #5 08-27-2010, 11:51 PM

I use an alternative refrigerant in my own car, originally R12. I know my system has a slow leak and do not wish to spend a lot of money to constantly leak an ozone depleting chloroflourocarbon. That said I'd never use it in a customer's car. Additionally,
I use my own personal recovery and charge equipment, not the shop's.

There are good alternative refrigerants out there, problem is that Dupont has had their hand in drafting regulations for long enough now that little else besides their spendy compounds meet regulations. Here in the US at least, the rest of the world chooses refrigerants based mainly on price and efficiency, not politics.

#6 08-28-2010, 08:16 PM

Politics, price of refrigerant, etc., have nothing to do with the downside involved with junk refrigerants. All of the junk refrigerants fall into one of two categories, they are either a blend or flammable.

The downside of a blend is that the components leak at different rates. This presents problems on two fronts; one is that to achieve the blend balance after any loss of refrigerant requires complete removal of the refrigerant, disposal of same and then recharging from scratch. Also one of the components of a blend is included for the specific purpose to circulate lubricant. With the balance upset, assuming the correct lubricant was used in the first place, lubricant will not be properly circulated.

The downside to a flammable should be obvious. As of about five years ago, flammables were completely outlawed in 18 states and the District of Columbia, this list of states might be even longer today.

I have never heard a reasonable justification for using any refrigerant besides 134 or 12. Both of these refrigerants are plentiful and inexpensive. In todays market 12 can be had for about $20 per pound and 134 for about $6 or $8. Any money saved by using a junk refrigerant will be eaten up in the conversion, lack of long term reliability, risk, problems finding someone to legally deal with it and on and on and on.....

deanyel · #7 08-28-2010, 10:01 PM

Anybody ever converted from 134 back to 12? Is it possible / lawful?

duxthe1 · #8 08-28-2010, 10:57 PM

Flammability of alternative refrigerants really doesn't confront me. R134 is flammable with a surprisingly low autoignition temp at pressures much lower than a/c systems typically run. R12 while not extremely flammable will burn and releases phosgene gas in the process. Everything in life has risks, and anyone willing to strap into a metal cage with large quantities of highly flammable hydrocarbons on board assumes a certain risk.

The regulations I guarantee you are political $$$ in nature. R12 wasn't replaced by 134A because it's good for you. R134a is a known carcinogen, linked with testicular cancer. Every time I get in a car with a leaking evaporator I exhale and hold it, grab my nuts, and try to get the windows down and aired out before I black out. Then I thank the government for looking out for my best interests.

david s poole · #9 08-29-2010, 10:50 AM

r12 will only burn in the presence of something more flammable burning [eg.gasoline] the most important reason that you don't want to convert to 134a from r12 is the molecule size of 134a.back in the 80's the evaporator cores were made of aluminum with u shaped end pcs epoxyed in.over the yrs that epoxy has petrified and the tiny molecules of 134a will find a way out of the epoxy and create a large leak in doing so.ask me how i know this.

durafrio · #10 11-16-2010, 09:11 PM

Check out duracool refrigerant, larger molecules and all natural. See www.durafrio.com

It will give you colder air, lower high side head pressure, and better performance in your automobile.

It is a hydrocarbon refrigereant.

durafrio · #11 11-16-2010, 09:20 PM

Duracool has a good conversion kit for r-12 a/c units. Inexpensive and easy to use.

See www.durafrio.com for more information.

ps2cho · #12 11-17-2010, 12:23 AM

Quote:

Originally Posted by deanyel

Anybody ever converted from 134 back to 12? Is it possible / lawful?

I converted from r134a -> r12....back converted.

Best decision I ever made thanks to Larry's recommendations. As LarryBible has stated, there is no reason whatsoever to be converting to r134a unless you want poorer cooling and a shorter lifespan for the compressor

#13 11-17-2010, 07:27 AM

ps2cho,

Thanks for the kudo's. I've dealt with so much hate mail lately, I really needed them.

I'm glad it's working out for you.

What you did makes WAY more sense than using a blend or a flammable. Probably saved you long term money to boot.

As for Duracool, well everybody has to sell something I guess.

DAVECAD2.0 · #14 11-17-2010, 10:35 AM

Don't do it. Use propane. Used in Europe and Asia. Not legal here but, if you're doing it yourself.........It's cheap and better than R12. Flammability is about the same. If you go with R134a you need more than just a "kit".
Which is usually nothing more than fitting adaptors. You need a larger evaporator core, larger condensor, different pressure switches, orifice, to get the same heat transfer rate. You also need to completly evacuate the system and replace the compressor oil. That's why most people are not happy with the results. It's like burning Kerosene instead of Gasoline.
You might be happy up north but, in the south..fagetaboutit!

ps2cho · #15 11-17-2010, 12:19 PM

Quote:

Originally Posted by LarryBible

ps2cho,

Thanks for the kudo's. I've dealt with so much hate mail lately, I really needed them.

I'm glad it's working out for you.

What you did makes WAY more sense than using a blend or a flammable. Probably saved you long term money to boot.

As for Duracool, well everybody has to sell something I guess.

There are plenty of people on craigslist selling R12 (You can legally purchase it with the intent to resell...to someone in your household for 0.01 of course)....I bet you could get away with buying it without even having the license. The whole CFC's making holes in the Ozone layer are about as scientifically supported as global warming has with the use of cars

It is all media and almost zero credible science.

Explosions due to improper refridgerant such as propane can and do happen:
http://forums.rennlist.com/rennforums/928-forum/145159-the-joy-of-ocic-and-one-sad-note.html

Only reason I would use propane would be for diagnosis only if you have a leak since it is so cheap and you can smell it. That is what I did for my leak so I didn't have to keep throwing $6 16oz cans of r134a in...After that my evaporator was pulled out, I flushed all lines fully, drained the A/C compressor. 100% r12 fresh system.

My dad's 190D shows paperwork of 6+ A/C compressor replacements. It it an r134a switchover....Makes you wonder....