Hope this helps: In your picture 1 (with the yellow check valve), the brown line goes to the ignition switch (another brown line goes from the ignition switch to the cutoff valve in back of the injection pump). The yellow check valve goes to the central locking system (one line to the driver's door and the
other line from the yellow check valve goes to the vacuum storage tank below
the floor for the rear hatch). The last line goes to the climate control system and this appears to be the one that is missing from the rubber connector (that has all the above). Plug the line that is missing (from the rubber connector) as well any other "open" lines and your TD should cut off immediately (after running a minute or two...to build up vacuum in the tank (below rear hatch...under the car). I just replaced all lines, rubber connectors on my 85 TD;now the car shuts off within 2 seconds.

Richard Greene