In reading that thread I believe that diagram in post #8 is for a 1980 240D and not yours. I believe the vac diag in post #3 (from ToomanyMBZ) of this thread may be yours:
vaccum problems>> 1981 240d Auto
Toomany MBZ - are you still around? I know your post is nine years old but do you remember if your diagram was for a '81 240D?