Originally Posted by jage
Diesel. Somehow thought that was in my Sig, duh
I don't see a sig, but the fact that it is a diesel just saved you a-lot of time and money! All of the vans have the same a/c related vacuum systems with the impossible to access vacuum reservoir directly above the passenger side inner metal fenderwell (at 12 o'clock above tire). However, the little reservoir is only necessary to hold vacuum pressure on the gas engines with no vacuum pump.
On a diesel, as soon as the engine is running, you have plenty of vacuum.
First, open up your access plate on top center of dash. Find black hose to controls, and disconnect. Buy 10 feet of silicone hose same size. I actually found pink(ish)/orange silicone hose sold in 10' length for @ $10 at Home Depot, in plumbing aisle. The black hose runs across towards passenger side and down firewall to ahead of where passengers right foot would be. It goes through a rubber grommet.
What I did was remove grommet by pulling towards you a few inches. There is a plastic ball and broken Y connector on factory hose. I removed them. Next, I used about 6' of scrap 12 ga. wire to stick inside the factory hose. I heat shrinked it to prevent it from slipping out. Then I heat shrinked the other end of my 12 ga. wire snake to the end of the new silicone hose (which was laying on passenger floor).
Now you can open the hood and find the black vacuum hose on far left where it goes from the wire loom down inside fender. If you have to, you can trace it from vacuum splitter near oil fill and follow it across. Free it up and gently pull from under hood, near passenger fender. It would help if you had someone else inside to feed the wire and new hose through. I did it alone and my wire snake broke off of the old hose when it was almost there! The problem is that the old rubber hose was extremely dry rotted! Good news was that I jiggled the wire from inside so I could hear it inside passenger fender. I wiggled it and rotated the wire snake until I could see it from under hood. I was able to fish it out of there with long needle nose pliers.
After that, the rest is very easy. Run the new silicone hose along inside the wire loom at the top of hood opening. Disconnect and remove old hose and connect and secure new one to black plastic vacuum splitter. Done! Cheers!