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Discussion Starter #1
So I am working through my vacuum system to determine what/where any leaks are. I have the glove compartment out and routing behind there. This part is all new to me since recently.

So I'm testing circuit III and IV, page 83-622.
Step 1 ... attach vacuum tester to connection 3 on the regulating value.
Step 2 ... pull out leak point 38 and close vacuum line blind. (uh? these Germans speak funny).

Ok so looking behind the glove compartment it sure does resemble the picture in the manual.

First picture is from the manual. You can see the coil for leak point 38.

Second picture is mine; coil is green and looks to be in right spot. So I follow the green coil and sure enough it goes into a vacuum connector.

I expect this coil to be a vacuum line; but look closely at the end of the wire in the last picutre ... it's copper electric wire ???

Is that right, or did someone who worked on the car before maybe shove something where it shouldn't have gone?

I know someone was working in this area because the stereo amplifier was wired in and they placed it up under here, too.

So if this is right, was does step 2 mean; I thought it mean to find the "specified leak point" and plug it so I could test connection 3.

If this is not right; what line should be in the vacuum connector; and what's the green wire for? lol. Sorry.
 

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R/C107 Moderator
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No help here on that coil of line is or what a "Specific Leak Point" is.
Did spot a couple of vac. lines that are disconnected.
 

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Discussion Starter #3
Thanks rowdie ... I forgot to mention that I pulled off that hose to the vent switch, the one on the right that you circled, made it easier for me to get my hand in there. As for the other one, the black one, that is a hose with a plug already on it, factory installed.
 

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One of the BW Old Guard/R129, W204 Moderator
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If this is not right; what line should be in the vacuum connector; and what's the green wire for? lol. Sorry.
It is common for "sintered" copper or similar to be used as a filter and/or restrictor in applications such as the "specified Leak Point". In other cases, the line that is designed to "leak" will be crimped almost shut... It is used instead of 2-way valves where-in the element is allowed freedom of motion that would be impaired if the system were totally closed. It also acts as a "damper" for the return motion of some diaphragms, so they function slowly, rather than "snap" open or closed. I believe it is more commonly used where there are double-acting vacuum "motors" employed.


Edit: Some of the above is inferred from a study of the function diagrams, and may not necessarily be true. Use at your own discretion...
 
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