85 380SL A/C question

[twochaps]

My 1985 380SL A/C is not providing any cool air. It looks like the refrigerant is properly low or gone. The car has been stored for several years. I know it is almost impossible to get the old freon, so I asked a mechanic what could be done without retrofiting a whole new system with the new refrigerant. He said he only needed to vacuum out the old stuff, install a couple of new couplings and then add the new R134 or whatever it is called. Question: Can or should this be done without ruining the old A/C system?

[cwmoser]

Originally Posted by twochaps

My 1985 380SL A/C is not providing any cool air. It looks like the refrigerant is properly low or gone. The car has been stored for several years. I know it is almost impossible to get the old freon, so I asked a mechanic what could be done without retrofiting a whole new system with the new refrigerant. He said he only needed to vacuum out the old stuff, install a couple of new couplings and then add the new R134 or whatever it is called. Question: Can or should this be done without ruining the old A/C system?

I got my 1983 380SL recharged with R12 -- took 2 pounds at $50/pound. R12 is available if you look around.

[airedale]

You can get plenty of R12 on eBay at $20. to $35. per can. Conversion has been hotly debated on this forum and after considering everything I stuck with the ( old ) R12.

[el Miguel]

I converted my 90 F150 pickup as you said and haven't had any problems. Its been 3 years now but, I would continue to use R12 in your 380. You can buy it online for about 25 bucks per can but you will need to be 609 certified. That too can be done online. Do a search, pay between 15 and 25 bucks, and take the test. You get a temporary certification that you print out and in a few weeks you'll get the real thing.
Mike
1985 380SE
1984 500SL Euro

[cwmoser]

Has anyone used the new Freeze 12 instead of R12 Freon? I read that it is supposed to compatible with the oil in R12 systems.

CW
www.380SL.8k.com

[RickM]

Originally Posted by cwmoser

Has anyone used the new Freeze 12 instead of R12 Freon? I read that it is supposed to compatible with the oil in R12 systems.

CW
www.380SL.8k.com

I've used Duracool and it worked fine...in fact cooler than original. It is, however, illegal to mix refrigerants. But if you're getting no cool air then there's probably not much in there. You have to consider that once you go with an alternative refrigerant that you have to mark the A/C components stating this so an unsuspecting shop doesnt contaminate their recycling equipment.

First thing to do though is figure where the leak was in the first place before anything else. This may require a charge with a dye or checking with a "sniffer".

[cwmoser]

I purchased my 1983 380SL July 1983, had to recharge it in June 1991, and again in July 2004. I went for a 2 or three years without AC before each recharge and it seems that my system is tight enough to last 6-10 years before leaking. I assume that there is some expected leakage of Freon anyway.

[dmorrison]

Originally Posted by twochaps

He said he only needed to vacuum out the old stuff, install a couple of new couplings and then add the new R134 or whatever it is called. Question: Can or should this be done without ruining the old A/C system?

Yes what he said is true. BUT, in a year or 2 you will be replacing the compressor and flushing the system due to a compressor failure.

Read this, it's called "black death"

http://www.ackits.com/index.cfm?fuseaction=black%20death

So yes you can install R134A cheaply but you will pay for your mechanics lousy work later.

Keep the car R12 if you can. If the car has "some " freon pressure, have the system evacuated, test the system for leaks, It should hold the vacuum for 30-45 minutes. If it does then you have slowly leaked the freon. 1/2 lb. leak a year is acceptabe, not good, but acceptable. If the system holds the vacuum then have the proper amount of R12 installed, I would include a dye for any future leak checks.

Dave

[RickM]

Id like to add that for 134 to stay intact "barrier" hose must be used. I don't believe this to be the case in 107s.


Right / wrong???