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Alex, I don't normally post in the AWD forum, but your rotor pics caught my attention. I'm not sure what you mean by defacing, but the condition looks a lot like ones I've recently had. I'm really curious, which brands of pads and rotors are these and roughly how many years and miles on them? When you installed the rear pads, did you "bed" them in or just start driving like many people do? Do the brakes "chudder" and get worse when hot?
Depending on the mileage, what I'm seeing here for wear is mild scuffing/scoring of the faces, so no big deal there. What I'm really noticing is the outlines of the edges of the pads. That's typically from the pad binder material melting and not depositing evenly around the rotor, such as parking/stopping with really hot brakes after a good highway drive and letting them cool. I've had a recent bad case of pad material buildup with Bosch Quietcast pads on fairly new Bosch Quietcast front rotors in one of my two 940s. The built up ridge of pad material allows a bit of rust pitting to show the outline of the pad. I even dial mic'd my rotors all the way around to prove it was pad material and not wear.
Two things you can try, and you may well not have success and decide to replace the rotors and as well the pads:
o Try re-bedding the pads doing a number of high speed stops to get the pads good and hot. Unfortunately, bedding rear brakes often takes a lot more effort than the fronts as the fronts do most of the braking. I tried this with mine and found that they did improve a bit, but that it didn't last long and the brake chudder problem started to return.
o Sand the surface first to try remove the pad material ridges then re-bed the pads. I used a metal flap disc and was very careful to work the high spots more than the low spots using a dial mic. Better would have been to have the rotors turned in a lathe, but that's generally not worth the cost, reduces the remaining life of the rotor and can actually make things worse if not done carefully. This re-surfacing did last longer, but the problems still eventually came back.
I eventually said screw-it and put in new rotors and pads. All has been fine since then. I'm no longer a fan of Bosch Quietcast brakes as I figure they've made too many compromises in materials for the sake of being able to advertise quieter braking, leastwise for the kind of driving I do.
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Dave -still with 940's, prev 740/240/140/120 You'd think I'd have learned by now
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