[A4] Strange Brakepad Wear

Pbadore at aol.com Pbadore at aol.com
Sat Sep 1 19:54:03 EDT 2007

Audi and VW changed the brake design on the A4 and B5 Passat to increase 
forces to the rear wheels compared with prior systems. Audi calls the system EBD 
for Electronic Brake Pressure Distribution. Audi describes its operation as 
follows: "Special software in the ABS control module regulates the brake pressure 
so the rear wheels cannot overbrake during excessive slip. This eliminates 
the need for the load-dependent brake power regulator or the pressure-reducing 
valve. The EBD control range ends where the ABS control is applied." As the A4 
and B5 Passat rear caliper and pads sizes were not increased very much if at 
all, I am guessing that the EBD asks the rear brakes to do much more work than 
the previous system that automatically reduced brake pressure to the rear 
brakes irrespective of slip levels. As a result the rear brakes probably work 
harder and wear out quickly due to their small size. 

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