Stay w/ R12 or convert to R134 - PeachParts Mercedes-Benz Forum

pexcellence · #1 06-21-2005, 04:30 PM

I have an 86 420 sel. The A/C has a low charge. There is a hose that is leaking from the drier to the condenser. There is still R12 in the system. Has anyone converted their AC to a R134? I read that it does not cool as well. Or should I stay with R12? The shop quoted about to $200 to evac and charge plus additional labor to change the hose and the drier and the cost of R12.

The other option is spend money on the DIY kit from ACkit http://www.ackits.com/merchant2/merchant.mvc?Screen=PROD&Store_Code=AMA&Product_Code=DIY-STARTER1 to do the conversion to r134

and learn to do this well. With this forum, I know I can tackle this job. Let me know what you guys think. I plan to keep the car as long as possible. Everything else in the car is working great.

Thanks,

John

DANSMB · #2 06-21-2005, 05:33 PM

I have converted 4 cars to 134 with no problems. I did this the cheap way, screw the fitting on the low pressure side and fill her up with one can oil and 134. Probably wouldn't hurt to have it evacuated but I have never done anything else. It's so cheap why not try it.

Dan

samiam4 · #3 06-21-2005, 05:52 PM

John,

IT really depends on your climate. If you live in the south and do stop and go traffic it will definately be noticably different. You can get an EPA license for R-12 for $15 on-line. R-12 gauges are cheap and the price per pound difference between R12 and R134a is not much this summer.

Do a search on Larrybible- there are some long threads on this subject over the years.

I would NOT convert my car.

Michael

1991300SEL · #4 06-21-2005, 06:37 PM

Lots of opinions on this one.

Some say that an original R-12 system will not cool down well after conversion to R-134a.

Others say it will.

There's a member here named Stan Pittman. Look at his profile. 30 yrs. euro car experience. He claims that the 134a conversions do work. I went looking for this thread, but could not find it. In it, he told Larry Bible that he was full of !@#$. Webmaster probably locked down the thread. Stan operates out of South Carolina. I lived not far from there once and summers are hot & humid. If R-134a works there, it will work in many other HOT places.

I believe that a refrigerant conversion is a lot like automotive body work. There's a lot of prep involved and if you do not do it correctly, the job will end in failure whether you're replacing an R-12 system with R-12 or converting an R-12 system to R-134a.

Larry Bible has recently mentioned $14.00 a lb. R-12. He has also mentioned refrigerantsales.com, so I assume he's buying it there. I just looked on their WEB site and a single 30 lb. cyl goes for $575.00. That comes out to $19.16 a lb. - not $14.00. Even in bulk, it's no where near $14.00 a lb., so I guess he's getting it elsewhere.

I saw R-134a the other day for $7.88 - a far cry from $19.16 and a lot more accessible.

Do the job right and R-134a will work.

lee polowczuk · #5 06-21-2005, 06:54 PM

I purchased my son's 300e from a guy in South Florida who spent about $3200 on a complete new system with r134a. (evaporator, compressor, high pressure hose,blower, drier)

It blows about as cold and powerful as any car I have ever owned

The replacement parts are the reason why I bought the car....

samiam4 · #6 06-21-2005, 07:05 PM

I believe Larrybible's point is philosophical-

A W124 system holds 2.2 lbs maybe a touch more- say 2.5 lbs. At $20 a lb, that is only $50 for R-12. And if you got your R134a @7.88 (is that a lb or a can?)- anyway we're spliting hairs over $20-30?? Correct.

There is no doubt you can convert it to R134a for $3200 and have wonderful a/c. But why not just replace a leaky hose, a few small parts and have it up and running for $200-300?

I've been in R134 converted cars and most I find inadequate. For W124's they wire the aux fan to be on when ever the compressor is engaged to help.

Michael

fastpakr · #7 06-21-2005, 10:24 PM

Quote:

Originally Posted by 1991300SEL

Lots of opinions on this one.
South Carolina. I lived not far from there once and summers are hot & humid. If R-134a works there, it will work in many other HOT places.

In a humid environment, the transfer rate of heat out of the air is much higher. The humidity HELPS the a/c rather than hurts it. It would be much more impressive to have a system that kept a car cool at 90* in Denver on a dry day than Miami or Charleston, SC with their respective humidity levels at the same temperature.

PaulSpringmann · #8 06-21-2005, 10:43 PM

I converted by 300SDL back to R-12; just was not happy with the cooling, especially after being parked outside. The previous owner had it converted to 134a only for the purpose of conversion in '98. The conversion was done correctly (complete flush, etc). I have the receipt and talked to the shop which performed the conversion.

Given my experience, I vote to stay with R-12 on a 126.

Stan Pittman · #9 06-21-2005, 11:43 PM

We have been converting to 134A since 1997 and have not had a complaint since. If you do it right you will have no problem. In my experience if done right it cools as good or better than R12.

96C220 · #10 06-22-2005, 12:51 AM

In my 1992 BMW, i faced this same dillema.

The guys on the bmw forum recommended a product called freeze 12. Apparently its an ozone safe R12 replacement, that is approved by the epa. You can purchase it and install it yourself, no epa certificate required. You can also add to existing R12 without having to evacuate the system.

I've had great results with it in the BMW. All my MB's at this point are R134a from the factory so I dont know how well it works with the MB's.

You can find it on ebay for cheap, a full kit with like 3 cans and the gauge and can tap is like 38 bucks.

Hope this helps,

George

samiam4 · #11 06-22-2005, 08:19 AM

te"In a humid environment, the transfer rate of heat out of the air is much higher. The humidity HELPS the a/c rather than hurts it. It would be much more impressive to have a system that kept a car cool at 90* in Denver on a dry day than Miami or Charleston, SC with their respective humidity levels at the same temperature"

No!! We are talking heat load- there is much more energy that has to be removed through the evaporator with humidity than on a dry day. You must be thinking of the condensor being more effiecent! And yes, denver @ 6,000 ft has thinner air, so it does remove less heat.

Stan : Where are you located ? What do you consider a "proper conversion"??

Michael

#12 06-22-2005, 09:20 AM

Statistically, even a "proper" conversion will only last about two years before compressor problems. These statistics are based on well kept records involving over 200 conversions in the hot Florida climate.

Now that R12 prices have come down there is just no reason at all to convert.

Good luck,

James L · #13 06-22-2005, 09:43 AM

I think the R4 compressors fail over time due to the extra R134a pressures. Maybe the A6 type compresssors in latter W124s hold up better to the R134A pressure.

1991300SEL · #14 06-22-2005, 02:04 PM

Quote:

Originally Posted by LarryBible

Statistically, even a "proper" conversion will only last about two years before compressor problems. These statistics are based on well kept records involving over 200 conversions in the hot Florida climate.

Now that R12 prices have come down there is just no reason at all to convert.

Good luck,

Looks like the stats you have are in conflict with what Stan Pittman reports. He does this for a living and since 1997(8 years) has had no come backs at his shop. His comment is on page 1 of 2.

As Stan said, it's all about doing it correctly. I would venture to say that many R-12 -> R-134a conversions are not "by the book" and I'd have to wonder if those "200 converions" were REALLY done "by the book".

We argue about oil, coolant and refrigerant. I'm out of this one.

What's next?....wiper blades?

boneheaddoctor · #15 06-22-2005, 12:40 PM

Quote:

Originally Posted by 96C220

In my 1992 BMW, i faced this same dillema.

The guys on the bmw forum recommended a product called freeze 12. Apparently its an ozone safe R12 replacement, that is approved by the epa. You can purchase it and install it yourself, no epa certificate required. You can also add to existing R12 without having to evacuate the system.

I've had great results with it in the BMW. All my MB's at this point are R134a from the factory so I dont know how well it works with the MB's.

You can find it on ebay for cheap, a full kit with like 3 cans and the gauge and can tap is like 38 bucks.

Hope this helps,

George

Freeze 12 is not a R12 replacement...it is a blend , do a search on A/C blends....
everything sucks compaired to R12....

Anna Kornicova and Rosie O'Donnel are both women...and they both work as women...its the same thing right?

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