on my 85 300d ,ive been tracking big vac leak,i can get car to shut off when plugging yellow check valve at firewall,testing line to resoirvoir is ok,line to drivers door does not hold vac ,opened drivers door panel and removed line from switch and plugged one end of it (solid yellow line )and mighty vaced the other end ,it will not hold vac which makes me suspect leak in main hose to master switch,anyone ever changed one of these(through door under dash through firewall) and if so where do you get one?vac pump is ok putting out 25 inches,i changed check valves in pump as they were leaking.

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95 e320,87 sdl,79 300sd

This video may help a little.

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www.myadvoforum.com
http://advopal.com

Most likely the line is broken at the door to post interface. You can probably splice in a short section of rubber vacuum hose in lieu of replacing the entire hard line. That might even be an improvement over the original configuration.

Does that one have a vacuum elbow (piece of rubber under the sound absorber)? I remember seeing a few of them down there when I had my car apart last year.

I cannot remember if that is a solid line all the way to the switch or if it turns and has a piece of vaccum tubing (elbow). There are a few of them right below the sound absorber right in front of the drivers seat (if I remember correctly). IE: Wherever you have a piece of rubber tubing is the place to look for a leak first.

I'm too lazy to look up my old vaccum diagram links. After just clicking on a few... They are all dead. As well as some in the Vaccum links section in the sticky on this site. Sorry....

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AJ

1985 300D (SOLD)

ive seen the video its helpful,im going to take line all the way out and inspect,if i dont see any obvious cracks ill put it in water under pressure like a bike tire,useing a rubber elbow is a good idea,i have extra rubber vacume hose.thanks for the input

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95 e320,87 sdl,79 300sd