Anyone know if I am supposed to be able to pull a vacuum through it with the engine on? Diagnosing my locks this weekend I found this to vent all the time. I had just replaced it and I believe it now to be faulty.

__________________
http://superturbodiesel.com/images/sig.04.10.jpg
1995 E420 Schwarz
1995 E300 Weiss
#1987 300D Sturmmachine
#1991 300D Nearly Perfect
#1994 E320 Cabriolet
#1995 E320 Touring
#1985 300D Sedan
OBK #42

In which direction? I have no experience with it but it would seem from the vacuum pump side, it should hold vacuum, ready to divert it to the shut off valve. But I assume from the shut off valve side it shouldn't because it should be venting the shut off while running?? All of this from my imagination.

__________________
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