Hey guys i just changed my vacuum pump due to leaking. I had one question. The hard rubber hose that connects to the plastic hose from the vacuum pump basically disintigrated when i tried to pull it off. So i cut it off, and installed just a regular rubber line with some hose clamps. Now, it looks like it is a little collapsed while the engine is running, but the brakes feel perfect driving. Has great power assist. No hard pedal or anything. Should i bother replacing that hose with the BMW version? Does anyone know if BMW sells that one piece separate from the whole line?

 

Yikes, I would... what of it keeps collapsing... or something else...

 

The BMW part looks like hard plastic (on bwmfans.info). That will be dimensionally stable (i.e. won't crush and won't collapse). Once had a Benz and the vacuum hoses were hard plastic, about the diameter of a drinking straw. But, if you look at the cross section, it has three internal chambers (imagine the cross section as a circle with a Y placed in the middle of the circle). That way, the hose could be routed and not kink or collapse and still pass a vacuum faithfully.

 

what type of hose did you use?
go to an auto parts store and get actual vaccum line hose, as they are more resistant to collapsing.

 

It is a vacuum/emission line. I "tied/clamped" at the bend so it cannot collapse anymore. It should be good.