I know that this has been asked 10000x, but it is difficult to find the one-stop solution. My '84 126 will not shut off and the doors will not lock. However, I recently replaced the vacuum box (shut off valve). Now, the car will shut off after about a minute only if I lock the all of the doors (which I have to do manually). I'm not sure that I installed the vacuum box correctly. How would I know? Does anyone have a vacuum diagram that they could send to me? Finally, after this thing is fixed, would anyone want to buy it? It's an '84 300D Turbo, 240K miles. It has new tires, brakes, shocks. A very dependable car. It runs too well...it won't shut off!
Thanks for the help.

Laneiac,
There may not be a "one stop solution" I have an 82 300D and it was plagued with a number of leaks when I bought it. None of the leaks on mine were serious enough to cause the fuel shut off system to fail or to make any one component fail completely. My series of leaks caused random and intermittent component partial functions. Due to the amounts of vacuum lost there was not enough residual vacuum to allow the component to function completely or punctually. I have not found all my leaks yet but as I find and correct leaks the "system" works better and more consistantly. The following thread may assist you if you have not seen it.

82 300TD A/C problem

Good luck.

Rick

Thanks. The information that you provided to me will be very helpful. My leak must be the size of Texas because the locks will not work even when the car is running. Some of the rubber hoses do need to be replaced, but they shold not cause everything to keep working. When I shut the car off, I hear what sounds like a vacuum leak coming from the booster unit, but I am told that is normal. The problem started when the car was rear-ended over a year ago (I don't drive the car much), so it could be in the trunk lock somewhere. Any suggestions on finding a vacuum diagram without having to buy the CD Rom? I remember finding a colorful diagram that someone made, but I can no longer find the site. Thanks again.

Laneiac,
You're welcome. I cannot help you with the diagram or CD as I have been too cheap to buy one. I can tell you that in the trunk of my car the two vacuum lines (as you look into car) snake along on the right side up near the top of the right wing behind the plastic liner and then come across the rear to the lock valve which is located behind a black plastic cover that poops off to gain access. While you are looking for the leak, if it is in trunk area, you could verify your key works in the trunk lock then plug off the lines and the remaining system may be intact enough to function while you are using the car. You could also disconnect the two main lines on the driver's side floor and plug the operating side and use the door locks manually also. Note if you plug all four passages when disconnecting the lines on driver's side the air in the lock valves will be trapped and may keep you from locking them manually.
As for the leaking sound from booster unit area; check all lines around the oil filter. There is a line that needs to be disconnected to gain access to the filter. These could be cracked or loose. (mine don't hiss) Good luck.

Rick