Re: what is exactly this bomb?

[quk@isham-research.demon.co.uk (Phil Payne)]

In message <EBEA7B28E298D2119D0300805F19CC14790054@mrxch4.pgsm.hu> Decsi Miklos writes:

> As some of you know  the rear brakes on my '83 80 Quattro don't work. When I
> inspected the brake system I found out that the problem can be either at the
> master cylinder or at a misterious device just below it. I think it is what
> you call the bomb. I talked to a mechanic and he told me that this is some
> kind of a brake pressure regulator.
>
>  Question: Is this thing really called as the bomb?

No.  On an 80 quattro, you won't have a bomb.

>  If yes, then how does it work?
>
>  If no, then what the hell is this?

Brake pressure proportioning valve.  Large weight inside slides about
to distribute braking force between axles - it also regulates
brake pressure to the left and right brake circuits in case one of
them fails.

It needs bleeding whenever the brakes are bled - right after the
master cylinder is done and before you start on the wheels.  Beware -
it's a 9mm bleed screw, which is quite unusual on brakes.

--
 Phil Payne
 UK Audi quattro Owners Club
 Phone: 0385 302803   Fax: 0870 0883933