carromeow,

If you go to Ebay under mercedes parts you'll always find a guy advertising a boolet that he published on just how to trouble shoot the system on 123s. Try his website **************.com to order direct. Once you've read the booklet you'll never have trouble again.

The yellow and red tubing in doors is lock and the yellow and green is open. Logical when you think of it. The brown tube from inside the hood is ignition switch and the other color, green, I think, is the vacuum controls for the a/c and heating.

Start solving your problem by isolating all the systems but one. Then you'll know which system has the leak and can attack only that one. Obviously, the hardest system is a/c and heating because of it's location.

Good luck.

Ben
www.reproduce100s.com