hello, I am Harris, new to this forum. My 300D has been having vacuum problem turning off the engine. Does anyone outhtere have a vaccum diagram for a 124 or a 1987 Merceds 300D. Any helps are greatly appreciated. Harry Sixto, Thanks for quick reply. My problem is a little more complicated. My vaccum lines to the iginition tumbler have been sucking air for the last 6 months. I replaced the iginition switch, and now my vaccum line to the igintion no longer has any vaccum. I suspect it either clogs with debris or a leaks somewhere. (I lost vaccum to the door system a long time ago!) Problem 2: I removed and checked the vaccum diagphram( to actuate the lever on top of injection pump). It seemed to hold vaccum and the seal is still good. When I put it back and connect vaccum directly from intake manifold to this diaghram, it did not actuate the diaghram. The position of the lever is now in a different position from that before I removed the part. I believe it has to be installed back in a certain way, and not just between the tongues of the other end of the lever. Problem 3: while hte tumber was out for 6 months, an electrical connector on the neck of hte tumbler was broken off. I believe it actuates the solenoid to allow the vaccum to certain place which I do not know. Obviously I need to buy another connector, but for the time being, a vaccum diaghram and detail on how to reinstall the diagraphm back on the injection pump would be greatly appreciated. Any helps are greatly appreciated. Harry