I posted a while back in an Audi forum about the brakes on the 4000s Quattro, I don't understand how they are routed in the car. I'll draw a diagram of how they're setup in my car:
Master Blocked off? x[ ]---> Down to Proportioning [ ] Valve (I think) Front Passengerside [ ]---> Front Driverside & Split down to Proportioning
In from split? --->[ ] [ ]