I have just begun working on my vacuun system to try and fix my locking system. After some preliminary work I found that my car would not shut off from the ignition.
I am begining to explore more and I found that there are two check valves that are blue and black. I was told by a source that the 1977 would have a yellow check valve. I was wondering if this difference was a change by MB or by the previous owner.

My cruise is also not working and there is a unit on the drivers side wheel well that I was told is the vacuum cruise system. If this is so there is a cable from there to the throttle linkage with a white plastic piece threaded into the linkage. I know its a long shot but this plastic piece is broken and I can't find a replacement. I don't know if that would fix it but I can't find the part anyway.

Thanks
Dave