Back story: Over the last month she would at random times not turn off. I did notice that the door locks wouldnt work when this happened. Figured it was vacuum issue.
I also noticed that if I opened the trunk (manually with key) it would turn off seconds later, otherwise it would run until I push the stop lever.

When I tested the lines under the hood here are the results.
Blue line : would only hold 10lbs
Yellows : none 0 lbs
The others all held 20lbs.

I am currently running withou the yellows connected and its shutting down fine and everything but the door locks work.

Anyone have a process to chasing down the culprit acctuator? Anything else I should test out first?

be careful you don't suck too hard. 20lbs is kinda high IIRC. most of the elements work in the 7-12 lb range.

yep.. the yellow/green and the yellow/red lines are the supply(lock)/return(unlock) for the locking system. the yellow/grey is for the vacuum tank. i assume you have a midivac. if you suck the yellow/grey it should slowly build and hold vac. the blue lines are the seat back locks and they can also go bummy. i disconected that whole circut a while back and i havnt missed it.

Yellow/green&red are going to have to be tested section by section until you find the problem actuator or fitting. The plastic vac hose can also become brittle and break.

- Take both door panels off to access the door lock actuators in the lower right corner of the door. take the right rear trunk liner out to access the fuel door and the trunk lock actuator has its own lil hatch right in the center back of the trunk.

vacuum pressure starts under the hood then follow it along the path... next stop, the master switch inside the driver door-->driver actuator--->under the dash--->passenger act.--->under the passenger floor mat and back seat--->fuel door--->to the trunk then back.

__________________
Current fleet
2006 E320 CDI
1992 300D - 5speed manual swapped

former members
1984 300D "Blues Mobile"

1978 300CD "El Toro"

How are getting 'lbs' readings? Most gauges read in inches of mercury. You can test lots of the various door lock items by accessing the lines under the floor mats on driver's and passenger sides.

__________________
1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

You don't say what car but....one line goes to the climate control which is accessed via the passenger tunnel carpet.
The slow leaking line is likely the climate vac pods. Most or all can be accessed with the dash installed (on an SD).

Another goes to the engine compartment and is easy to access.

Another goes to the door locks. There is a pod in the trunk by the spare tire. Lines run under the carpet & back seat via plastic channels on both sides of the car.

I think there is a reservoir under 1 or both fenders behind the plastic fender liner.

__________________
85SD 240K & stopped counting painted, putting bac together. 84SD 180,000. sold to a neighbor and member here but I forget his handle. The 84 is much improved from when I had it. 85TD beginning to repair to DD status. Lots of stuff to do.

Sorry - 1983 300CD

And I was thinking INCHES dont know why i kept putting lbs.

I was measuring at the 4 way split under the hood. I'll start by plugging the return line from the trunk acctuator. Then work my way from the drivers door as Phillytwotank described.

Thanks! I wouldnt have known the rout the lines took otherwise!

This is a good thread describing the W123 Vacuum system.

W123 Vacuum InterLock Diagram

When I read in the first post "Blue line" that was the CD tip off on the model.

Charlie

__________________
there were three HP ratings on the OM616...

1) Not much power
2) Even less power
3) Not nearly enough power!! 240D w/auto

Anyone that thinks a 240D is slow drives too fast.

80 240D Naturally Exasperated, 4-Spd 388k DD 150mph spedo 3:58 Diff

We are advised to NOT judge ALL Muslims by the actions of a few lunatics, but we are encouraged to judge ALL gun owners by the actions of a few lunatics. Funny how that works