How much boost BPV spring should hold ?

[kwlw]

Hi,

I have done pressure test for turbo hoses on my 3b. All hoses seem to be holding pressure up to 1.2 bar, ant the leaking air amount is minimal (pressure drops, but slowly), no big whistles etc.

So after that I've tried to pressure test bosch BPV. When I applied pressure to the "side" - it held only 0.2 bar. Is it normal ? As far I understand, under boost it gets some boost through "control" hose, and the spring should hold only difference of these pressures. Also that thing is holding lower pressures ok, as far I understand it shows, that diaphragm is ok. However 0.2-0.3 bar seems to be too small. Does anybody has played with BPV and pressure ?

Sau

[Billman]

Yes, but under boost the little vacuum hose also has boost!

[kwlw]

Yes, but under boost the little vacuum hose also has boost!

I know that, but in case small hose drops, burns, torns or is otherwise damaged - such valve creates lots of boost pressure leak . I'm interested in what pressure should it hold, because spring can be worn, however I don't want to buy new valve which will behave exactly the same.

Sau

[S2central.net]

The control line into the TBV should hold boost all day long - unless you have a leak. I normally test with about 1bar boost on control lines and also with total vacuum...

Your TBV must have a damaged diaphragm or split body if it can't hold 0.2bar boost.

Make sure you have the TBV connected properly as well...