Stirring the controversial pot, again.

[Bernie Benz]

Hi Guys,

Inasmuch as these lists have been devoid of inspirational controversy for a
while, I thought that I would expound on the virtues of Audi's
(nonexclusive) passive 4 wheel brake pad wear indicating system.  Mine
activated with an audible warning of a rear pad problem this week.  This
audible warning occurs when the pad's backing plate, being wider than the
pad, rubs on the rotor's original machined surface, those two annular rings
of unworn rotor surface either side of the active pad contact area.  This
passive warning is much more attention getting and reliable than is the
active "red light" system used exclusively on some front pads (pads without
the active sensors are cheaper than those with, and further, allow more
complete pad useage before calling for replacement).  The remaining pad at
passive warning is always equal to the rotor wear on that side, in my case
about 0.050".  This is but yet another reason for never machining rotors, in
addition to not screwing up a good true surface, don't destroy the pad wear
indicator.

Bernie