Hi, I'm working on the vacuum system on my 84 300SD. I think that the vacuum lines going to and coming off of the switches on top of the valve cover have been mixed up. Can anyone tell me which one goes into which orifice?
Thanks
izick

Take the lines that go to and from the valve cover and toss 'em.

There are three of them.

One goes to the temperature switch on the passenger side of the head. Toss it.

One goes to a supply vacuum T in front of the oil filter. Toss it. Remove the T and connect the two remaining lines with a short piece of vacuum tube.

One goes to the vent vacuum T.....also in front of the oil filter. Toss it. Remove the T and connect the two remaining lines with a short piece of vacuum tube.

You're done.

Nice and clean engine compartment.......without any EGR.