I'm trying to fix the locks on my 1986 190e (which is for sale, btw). I've determined that the pump works fine and there is no vacuum leak near the pump. Yet none of the locks work. The one on the rear right door, which is closest to the pump, is the only one that "almost works". My question is: where should I look for vacuum leakage? I already checked the passanger door, and everything seems OK. Do I have to go through all the doors? Is there a place where leakage is most likely?

Thanks,
Tavi.