Originally Posted by yogarda

I'm sorry for not specifying... This is a newly-acquired '83 300D Turbo, and I have inherited vacuum problems in a variety of places, which I am slowly pinning down each one thanks to the wealth of info here.
One of my three lines goes back to the lower nipple on the VCV atop my IP. One is a direct input via a couple of 3-way splits from the brake booster line, and the third heads off to the EGR. So not everything here is isolated to EGR function, though I do have my EGR line plugged to help me diagnose the rest of the system.

I was actually not intending to get into my own specific problems here since it appears there's plenty of existing threads that descibe my problems and diagrams to help me... But in the process of t-shooting my two 3/2 valves, it occurred to me that I'm not sure how they're *supposed* to work. I can get them to hold vacuum on the one port but, as described, they quickly leak their vacuum when the button is depressed. Knowing that vacuum venting is a part of this whole process, I wasn't sure if these things vent vacuum when depressed, or are supposed to transfer vacuum to the other two nipples in a leak-free manner.

Thanks for your quick reply.