1970s/80s Mercedes-Benz door lock vacuum actuator replacement

[@sirjunius]

Michael - thank you for this and your other recent videos. I love the focused, practical walkthroughs as well as the tips and tricks here and in the other videos. I have a 1973 280SE 4.5 needing TLC that will benefit much from your walkthroughs. Please keep up your excellent work. We the community of Benz lovers deeply appreciate it.

[@rmulvihi0521]

Thank you. Excellent and to the point.

[@georgecurtis6463]

One thing I have found in all my years of working on mb vac systems is to use a vac gun or whatever one wants to call it and pull a vac slowly. Pulling it fast can cause the cracked rubber to move fast enough to actually seal itself. So going slowly doesnt allow it to do this. If you keep pumping slowly and after a bit it starts pulling a vac then you can be sure the diaphragm or whatever is good. If you keep pumping and pumping and no vac then you know for sure there is a leak or crack in the diaphragm. And of course, make sure you check both locking and unlocking circuits. Once you find something and take the panel off, recheck at the vac unit. Have found cracks in the lines through the door or the connecting hose to the vac unit. Course back in my days the diaphragm were individually available. Sad they no longer are.

[@rmulvihi0521]

Is there anything to put on the rubber that will keep it from drying out and cracking?

[@michaelthemercedesguy]

Not that I'm aware of. The only solution is to replace the diaphragm, but replacement parts are getting harder and harder to find.