I haven't been able to find anyone that claims to have any experience with Cryoseal on a car like mine, and I don't think I will try it unless I can find someone who will give me some sort of strong assurance.

I do appreciate all the advice on this. I will definitely install a copper evaporator if I replace it, but R12 is not available to anyone except people who stick you for a minimum of $150 just to recharge it. I HATE being dependent on such situations.

A assume that in the meanime, I can recharge this witl a can of oil and a can of Freon 134a on a temporary basis, without any majot problems.

Apparently, the MB system is less reliable than the one on my Hyundai Excel (the model they sold in pairs), as the 89 Hyundai has needed only a new AC hose since 1989. I bought it from the original owner. So far it has 89K ansd the original brakes. But it DOES ride like a Hyundai. The Mercedes is a joy to drive. The Hyundai is a lot better than a 51`Chevy, but less fun. I bought it to avoid having to rent cars when mine needed work,for $250.00.

I have had bad luck with every dealer I have ever dealt with, not just in Miami, but in Seattle, Kansas City, West Virginia and Maryland. All overpriced, all slow, all horrid liars. I know for a fact that two of the salespeople at Warren Henry are impossible smartasses. Of course, salespeople are usually smartasses in the US.I noticed that in the dealership, a customer who wanted to talk with the mechanic was told that the mechanic was busy. At the local Mercedes independent shop I can talk with the mechanic, which I consider pretty much essential.

I bought this car last year from the second owner, who owned it since 1992.

Incidentally, when the AC was working well, it would cut off and blow uncooled air about every 20 minues for about 45 seconds, then blow cold again. I was told that this has something to do with a selector switch. At one point it began blowing hot air. This turned out, I was told, to be due to a false contact in the fusebox. It didn't cost extra to fix it, so I assume that this is correct.
I don't suppose that the switch could be related to the very small leak the mechanic said he detected under the dash? I suppose some sorts of switches could in fact leak.