I took my car into the local MB dealer. They said it is the MAS too. Also said that I need a A/C system tune up to R134. ($700). I think i'll call Cool-It. Problem is that it cools well and I've heard that the R134 is not that efficent. I need all the cooling power i can get. These dark brown wagons really heat up in the summer. Thanks for your help.
90 300TE4MATIC (124)
79 300SD (116)