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View Full Version : M30 booster check valve - what's the extra nipple for?


Mobius
09-09-2004, 09:05 PM
Hey all..

Quick question:
http://home.comcast.net/~rjchristie2/SA/535i/IMG_3284s.jpg

I'm trying to trace down a vacuum leak, because my engine's throwing lambda codes when I sit at idle for more than a couple moments (as soon as I blip the throttle, the CEL turns off).

Anyhow, after hearing how EVERYONE seems to have a busted brake booster check valve, I decided to just go and replace mine since the hoses were about to turn to dust anyways.

I was surprised to notice that the new valve I recieved from BMA had a little nipple coming off the engine side that allowed the vacuum to reach the atmosphere - I didn't think mine had that, so I just cut a little piece of vacuum hose and shoved an appropriately sized screw in one end and capped the thing off.

Then I pulled the old one off - and apparently the little nipple that I didn't think it had was actually completely snapped off (see picture). Hello vacuum leak!

So, I guess this question is mostly out of curiosity - what the hell is the nipple for? Some option I don't have?

(Even if that hole wasn't there, the old hoses were so cracked on the underside that if I plug both ends I can breathe through the thing. Good god. Vacuum leak central. Note to all M30 owners REPLACE THIS WHOLE DEAL NOW.)
winfred
09-09-2004, 10:01 PM
i have never seen anything connected that bastard in 8 years of working on bimmers, i think it's there to be broken off
gale
09-10-2004, 12:00 AM
Dat be the "James Bond" version:

http://www.nmia.com/~dgnrg/james_bond.jpg
Mobius
09-10-2004, 12:37 AM
i have never seen anything connected that bastard in 8 years of working on bimmers, i think it's there to be broken offGoddamnit. And here I was thinking BMW engineers were infalliable. Never designing something so that it didn't have SOME purpose...

My dreams are crushed. :(
Mr Project
09-10-2004, 07:36 AM
Yeah, mine was cracked there too, and never had a hose there in my ownership. JB Weld solved that problem pretty quick. :)
535ise
09-12-2004, 05:27 AM
That vacume hose connects up to a nipple on the bulk head,just to the left of your heater hoses,it's quite hard to see though.
winfred
09-12-2004, 09:32 AM
i figured it was for a euro car


That vacume hose connects up to a nipple on the bulk head,just to the left of your heater hoses,it's quite hard to see though.
Mobius
09-12-2004, 04:37 PM
That vacume hose connects up to a nipple on the bulk head,just to the left of your heater hoses,it's quite hard to see though.Huh. Definitely not seeing it.

Yeah. Must be a european option or for some vacuum operated climate control version..