Hi All,
First a quick thanks to all. I was up late last night reading through past posts on the vacuum system. Sunday I lost my brake assist and the engine wouldn't shut down. After work today I picked up a mightyvac at the autozone and in the fading light I started checking through different vacuum lines. I found a line that wouldn't hold vacuum and plugged it and now my brakes work and the engine shuts down. I'm posting a photo of my fix and my question is: Have I (as I think) disconnected the vacuum from the interlock system, and is there any reason I shouldn't run the car this way for a little while? I kind of need to drive a few miles tomorrow but I don't want to do any damage. Thanks again.

Cheers,
Peter

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I have been mistaken before but I think that just goes in the cabin to operate various things, i.e. locks. I could be wrong and usually am.

Kevin

Good diagnosis... yes, the yellow check valve thingy is indeed the feed to the door locks and other stuff inside the cabin. Safety 1st... glad the brakes are working with the booster assist.

Now you must find the offending vacuum drain. It probably is one of your door lock vacuum elements which can be found by testing them one at a time. It only takes one to go bad to drain your whole vacuum system. Do a search on door locks and vacuum leaks.

Good luck

__________________
Mr Goodfahrt (pronounced FAIRT... means "good trip" in German)

1982 300D Turbo Pastel Gray (off-white) 200k+(?)
newbie but willing

Thanks guys,
That's what I thought, but I felt the need for a little reassurance. Searchind past posts was invaluable to me in diagnosing the problem and coming up with a quick fix. This came on kind of suddenly late Sunday and I only got about an hour of daylight when my wife could look after the kid while I sussed this.
Before that I only had a slight idea about all the different things the vacuum did. Now I'm gonna fix the interlock which I'd never really planned to do. First the sunroof! Thanks again you guys rock.

Cheers,
Peter

The yellow lines supply the locks, but no "other stuff." Just the locks. Check the fuel filler and trunk pods first as they are less robust than the door elements. They're also easier to get to.

__________________
Rick Miley
2014 Tesla Model S
2018 Tesla Model 3
2017 Nissan LEAF
Former MB: 99 E300, 86 190E 2.3, 87 300E, 80 240D, 82 204D Euro
Chain Elongation References

I checked my system and the two lines go to different places. One goes to the door lock system and the other goes to a vacuum reservoir in your trunk. This almost never goes bad, so your leak is most probably in a doorlock actuator in one of your doors.
One other thing you might check is the yellow check valve that the two lines come out of. It should allow vacuum in only one direction. This can be tested by removing it and applying vacuum to the single end. You should be able to suck but not blow through it. Good Luck

__________________
Mr Goodfahrt (pronounced FAIRT... means "good trip" in German)

1982 300D Turbo Pastel Gray (off-white) 200k+(?)
newbie but willing