I rechecked the vacuum and found it to be nearly 15" with only the vacuum pump and brake booster in the circuit. There is a 3 way connection that goes to a brown tube, a green with yellow stripe, and a yellow thing that looks like a check valve or filter of some sort. Off the back end of this comes a yellow line with grey or black stripe. With the key off but engine running, i can make it stop by pulling the yellow line off the yellow filter looking thing, and blocking it with a finger. It takes about 3 or 4 seconds for it to shut down. So hopefully i am on the way to finding the problem, downstream of that yellow /gray tube, which is for the locking circuit (?). Weird thing is that the lock have always been iffy, and are about the same. All these tubes go thru a rubber thing in the firewall, so i am hoping to find it on the other side and see where the break is. Or maybe just block it off, who needs door locks?!


Thanks for all the advice; you fellow Mercedes victims always come thru for me!