Vacuum

[Willie White]

I am posting this with the objective of learning more about the vacuum system on my 1980 300 SD 116. I have battled thru the "no door lock", "no engine shut off", "no CC" and bad transmission shifting problems and now have gotten thru all these after a fashion. Now I have the usual defective CC servo which I have bypassed by way of a valve which enables me to shut the heat off in the summer(No AC). I can ,by necessity,live with this. The transmission shifting is tolerable with some slight flaring at times between 3 to 4. Depends on throttle position. Downshifting is smooth at all times.

The engine I now have came from an 82 300 D complete with transmission. The combination had less than 50K miles. I had all seals in the engine replaced and had the tranny rebuilt because they had been sitting for an extended period.

The people that replaced the engine knew less about the vacuum system than me.(I found this out after finding my way to this forum). This newer engine had the variable valves on top of the valve cover pan and they contributed to the aforementioned problems. I think it was Steve Brotherton who told me to eliminate these and that was the beginning of the solution to most of my vacuum problems. My EGR system developed a clogged vac supply line soon after I became aware that the EGR system existed.

Which brings me to here. I plan to keep this car for the duration. I have no major problems other than the usual oil leaks.Also, the usual adjusting of valve clearance a couple times a year . BUT--I know that vacuum problems are lurking in the bushes just waiting for the most inconvenient time to strike.I have not the option of taking any problems out to a shop. I am supposed to be retired and my income is based on my 1990 salary. ( I was paid weakly). Beside that is the fact that know-how about this system is,to my knowledge, not there

I have made a diagram of the engine compartment vacuum hookup as it now exists. My problem is that I have not a clue where the lines go after they enter the interior near the brake booster.I will try to post that diagram in the hope that someone might help. I have compared my diagram with the PeterSmid diagram for the 80 300 SD and find no similarity. If a different diagram or other information need be sent that is too bulky to post here my email is Tinwillie . I thank everyone in advance.

I have read all the threads I can find about this system and find that the ones by Brian and Sam are exceptional. I recognize that there is a wealth of knowledge on this forum. THANKS