Thanks for the suggestions. Euro I've never used cryo-seal or anything to seal the system. If I understand you correctly, the pressure gages should be hooked up while the air conditioner stops blowing cold air. I do seem to recall that when I started taking the car to be checked, an AC repair shop said that it was pulling into a vacuum, but didn't diagnose the problem (maybe he didn't want to work on a Mercedes).I'm guessing he was talking about the low side.Gilly, would an airconditioner repair shop be able to check for bad evaporator temp sensors or is this something only a Mercedes shop would be able to check? Are they reasonably easy to get to or do you have to remove the dash board?
Bob

__________________
BobH 90 R129