While replacing the compressor, drier & expansion valve, I have run into troubling reports (from a local mercedes parts & repair poviser) regarding failure rates on A/C repairs. He reports that over the last twenty years he has tried most "reputable" brands of rebuilt compressors, including rebuilds supplied by mercedes, and has never found what he feels is a consistent supply of rebuilt compressors.

More troubling, he reports that it is almost impossible to adequately clean the manifold hoses assembly that attaches to the rear of my compressor.

Tonight, after removing the manifold from the old compressor and cleaning it with brake cleaner, I noticed that one side of the ports was still covered with a dark gray film. A shop rag produced black residue after minor rubbing inside the ports. No amount of brake cleaner will touch the film. This film also exists in the manifold hose assembly (at least at the metal portion that bolts to the A/C compressor manifold).

If this type of film is spread throughout the system, prehaps this is the casue of post-rebuild failures.

Does anyone have expertise that can help me get my system adequately clean inside?

Also, what is the track record regarding the life of the stock condensors.

Thanks,Bob

Rick - I saw a photo the other day at an A/C website - can't remember the place I was at. They talked about something called "black death". It's supposedly more prone in Ford units - teflon was used in the compressor. Here's some text info I found. I realize your Benz does not likely have teflon in it's A/C system, but your may have a similar situation.

http://www.autoacrepairs.com/index3.html

You may also want to do some reading on this site and perhaps submit a question or two:

http://www.ackits.com/cgi-bin/ultimatebb.cgi

This is a bulletin board dedicated to the assistance of DIYs who want to learn to do automotive A/C work. The experts who contribute their know-how to this board do an excellent job.

Hope this helps.

__________________
Ted
1979 240D
165,000 miles

Thanks for all your input. I have already removed the drier and compressor, removed the manifold hose/pipe assembly and the hose from the condensor to the drier. I also flushed the condensor and the evaporator & associated lines with laquer thinner and compressed and dried air. The compressor still turns freely and the A/C worked great until the shock absorbing material on the clutch failed.

It seems that, in addition to the $900 I have already spent for parts and freon, I can either spend another $1k for new condensor, evap (and the fun hours to replace), and all new lines, or roll the dice and put the system back together with my new drier, rebuilt compressor, and lacquer flush.

No one has commented on the life of the stock condensors - any experience?

Moraine:

Thanks for your helpful comments. I visited the recommended web page and was directed to the black death discussion you referenced.

I am going to roll the dice since I have already purchased a rebuilt compressor.

This is my son's car. Due to my lack of discipline, I purchased a $5,600 car that now has ingested $11k of my $$$. I would have bought him a new civic if I had understood the reality of these cars. At least he loved the car - and me too, hopefully!