Hi,

Ok I have a 240d 75.

Car was after driving on freeway, coming to stop at end of exit, car would spew out massive amounts of smoke, and eratic idle, using rpms going up.

Had vacuum pump seals etc replaced - repair kit.

Great for one week - now lost door locks - Hard Brakes (no Brakes) when car is running (No Booster), Car spews out smoke again after a short drive and at operating temp.

Seems to be conflicting info on wether its the Brake Booster or Vacuum pump, Looking for a difinitive way to test.

Cheers
GS

I believe in that year there is a plastic hose going from the vacuum pump over to the air cleaner. check to see if there is oil in that hose. If there is, you have a failed vacuum pump diaphragm. On my 77 300d, that hose is clear so I would be able to see oil inside it.
I don't think a failed vacuum booster will cause smoke unless it is sucking brake fluid through the system and into the intake somehow and I really can't imagine how this would be happening.

__________________
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