In a message dated 1/10/02 11:27:21 PM Pacific Standard Time,
korkwood@WSHOST.NET writes:

<< This is brake proportioning valve even though VW calls it brake pressure
regulator.
 You described its location correctly. The ordinary pressure regulator just
reduces
 pressure in outlet according to how it is adjusted. BPV splits pressure in
such way as the front brakes get almost 2 times the pressure vs rear brakes
to prevent locking up. It is preset by spring inside. It may vary somewhat by
inertia when driving. >>

Leon,

I agree that the VW Brake pressure regulator is in essence a proportioning
valve. However, when most folks use that term, they are referring to the kind
with the knob that you can adjust. I disagree that Vanagon version is
adjustable automatic or otherwise. You said it yourself, "It is preset..." I
would think you have to disassemble the darn thing to make any kind of
adjustments. I would be very interested to hear opinions on this.

BenT