90 is hot, I think it only got up to 50 degrees in Wenatchee, with a Wind Chill of like 30 degrees

R12 systems have not been discontinued due to "obselescence of R12. R12 functionally is the best refrigerant you can use. Other factors are what made them stop making it.

The systems designed for R12, work BEST with R12, and the environmental mysteries aside, nothing beats it with no downsides.

Just because you work on the car yourself does not mean that it will not be wrecked and the refrigerant recovered into an R12 container spoiling all the refrigerant in the container preventing its reuse.

R12 is available, and the price is coming down due to decreasing demand due to so many cars requiring it are hitting the wrecking yards every day.

Its a free country so you can use what you like. I just want to make sure you know some of the pros and cons involved.

Have a great day,

In that case it might burn. This does not seem any more dangerous to me than running cars on gasoline. How much more likely is it that the propane refrigerant might explode than a gas tank? Perhaps it makes a diesel more dangerous.

__________________
1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

What would you tell those poor souls driving around with gasoline powered vehicles? God forbid that the gasoline lines would be breached during a collision and that they are also carrying around 20 gallons of gasoline where they may be rear ended. That is alot more risky, in my opinion, than my 16 ounces of duracool.


All I'm saying is that a risk assessment must be made and gather all the correct facts before you make a decision. We shouldn't come to conclusion without investigating the facts first. Duracool isn't for everybody. My decision was based upon the performance, cost and safety. If people want to use the lower performing, less efficient r-134, more power to them.

Herb
'82 240D
'87 300SDL
'92 300D 2.5 Turbo

Larry,

I agree with you. R-12 is the best refrigerant if it was readily available and plentiful, but ask yourself this question: How much longer is r-12 available? Will the price come down to $6 a can like the duracool price? No it won't. Also, there will be a time when distributors will no longer carry the stuff and stores will no longer stock it because they don't want to carry it for inventory....its too expensive to carry something that doesn't sell. There will be a time when there won't be a demand for r-12 because it will no longer be available. People won't put up with that along with high prices. They would have converted to the 134 or alternative long before that. You are also right about cars coming into the wrecking yards but then that supply of r-12 is limited too.

Herb
'82 240D
'87 300SDL
'92 300D 2.5 Turbo

Herb and Kerry, I will be right back...

This is a little off-topic but I have found that a quality window tint job with metalized film will reflect a large amount of the energy of the sun resulting in less of a load on the AC system. It doesn't have to be dark tint, just the metalized stuff that really reflects the radiation. If you have to convert to r134 the tint may make up for the loss of efficiency. RT

__________________
When all else fails, vote from the rooftops!
84' Mercedes Benz 300D Anthracite/black, 171K
03' Volkswagen Jetta TDI blue/black, 93K
93' Chevrolet C2500HD ExCab 6.5TD, Two-tone blue, 252K

My 84 has the original R12 in it, but it is VERY weak (assuming a VERY small leak!?). Will I have to pump it down in order to put more freon back in? I would like to stay with R12, if at all possible. Does anyone know what the current cost per lb. of R12 is now roughly?

Thanks,

__________________
Jeff M.
Mercedes W123 DIY pages are now located here.
1983 / 1984 300D Sold
2000 CLK430 Cabriolet ~58k Sold
2005 Avalanche 4x4 ~66k

In order to check it for leaks the shops put a full charge in and then go ' sniffing'.... you can make a pretty good guess as to whether a system is leaking by pulling a vacuum... but not for sure because you are loading the seals in the opposite direction which they will be being used...
And you don't want to fill it with any correctable leak extant... ( some automotive systems are designed to have the front compressor seal lubed by a small leak of coolant (which is mixed with oil)... so you never really have it completely sealed when moving seals are involved... but for many reasons you want to find any and all leaks and fix them before charging the system.
I do not know what the current cost of R12 is.... but it is pretty easy to check on Ebay for concluded auctions...
I paid $18 per 14 oz can ( including shipping ) last summer...
You are wise to stay with R12 if you can possibly manage to.

Isn't it against the law to have R-12, buy R-12. sell R-12. and recharge w/ R-12 without proper licensing?? At least that was my understanding.

__________________
1984 190D 2.2 Auto 220k
2001 Jeep Cherokee Sport 70K
2004 Lexus RX-330 ??K
2005 Chrylser Crossfire LTD 6K

Play guitar? Go to www.cyberfret.com for free online lessons!

Yes I believe it is illegal, EPA 609 certification for automotive systems is needed. Anyone can read the manual online, then for $20 you can take the test online and upon a good grade you get your certification.

I don't think I'll bother looking for a leak, I mean right now driving down the expressway I can feel it working just there is hardly anything there. Well the almost only time I used it was back from NC when it was around 90 it took the interior down to around 75 on max A/C. Wow that isn't bad at all for price, I was thinking it would cost a lot more than that.

__________________
Jeff M.
Mercedes W123 DIY pages are now located here.
1983 / 1984 300D Sold
2000 CLK430 Cabriolet ~58k Sold
2005 Avalanche 4x4 ~66k

190D22, since you posted that right after my post I assume you were addressing me... if you check in the 8th post in this thread I mentioned the open book certification test....

airfoill,

I was obviously not clear in making my point about the cars requiring R12 hitting the wrecking yards. Becasue the newest of these cars are about 11 years old now, there are tons of them being taken off the road every day.

I was not saying this to point out the availability of the R12 in these cars that is there to be recovered, although that does add to the available supply. My point is that this means that the DEMAND for R12 is rapidly decreasing. Most cars don't stay on the road as long as do our MB's.

So, this gets to "Supply and Demand." A few years ago, R12 got up to as much as $80 per pound. It can now be purchased readily for under $30, with a 609 certificate of course.

Although you can no longer buy R12 at K-Mart for $.59 per pound like you could at one point, it is readily available and I fully expect that it will be available as long as I am on the Earth. There again, Supply and Demand. The demand is rapidly decreasing.

Again, everyone is free to use what they like and they can even justify it in their own minds however they like.

Have a great day,

I've done 2 of these conversions myself, both on Saab's. The most important things I learned were from an A/C shop. Saab's as do many other cars, have an adjustable expansion valve, each manufacturers system is different as to how much adjustment is needed, if it's adjustable at all. Also r134 pressures are lower than in an r12 system, in fact, when properly filled, you will see a steady flow of bubbles in your sight bubble. Not a good sign in an r12 system but needed in an r134 system. r134 systems are also much more sensitive to atmospheric temps, so when charging this kind of system, you need to be very careful about your pressures. You have to go to an actual A/C shop for the proper information to do this job correctly! In the case of this job the dealer is most likely not your best bet. As for you naysayers out there, my conversions have worked great thanks to the help I got from my A/C shop. I drove my Saab down to Houston last June and kept four people nice and cool in 95 degree,90% humidity weather during the week. I aso visit my parents in Phoenix regularly and have no problem keeping cool there either, even when it's 110+ degrees. r134 can work well! But it must be done properly.

I mostly agree with F1-Bob as far as 134 conversions go on MOST cars. There are many cars that are good candidates for 134 conversion, and there are many cars that are not for various reasons.

The 123's are marginal, but if done properly can get by. The 124's are not good candidates at all. The two components that need to be considered when deciding on conversion are basically condensor and compressor. The condensor must have adequate thermal capacity and the compressor must be of a type that will both seal with 134 AND be durable with the additional high pressure requirements.

Note that I said for 134 conversion. I have converted a number of various vehicles to 134, one of which I have since reverse converted to go BACK to 12. What I personally WON'T do is use an alternative such as DuraCool, Freeze 12, etc.

The only two refrigerants that I will even consider are 134 and 12.

Have a great day,