Weed Racer

I put slotted and drilled rotors and semi-metallic pads on my '05 last Friday and have a few questions and observations:

First, I had a hell of a time getting the rear calipers off due to quite a deep ridge at the outside or the rotors. At the time I figured this was normal enough since I had 65,000 miles on the original brakes (I drive lots of highway, and am generally easy on the brakes).

The installation went very well, but after a test drive I noticed that the contact area between the pads and rotors on the rear wasn't as "complete" as it should be or is on the fronts. The rotors were plated with something silver (zinc?), and it wore away immediately where the pads contact the rotors.

In the rear I have what amounts to about half contact on the outer rim of the rotor, and I can see where if this was happening before the new parts were installed, that this would be a likely cause for the ridge I mentioned earlier, and an assurance that it will happen again

Anyone experienced this before or have any ideas?

When I look at the rear calipers, the pads are seated well within the castings and are not crooked in there. The contact pattern is identical on both sides as it turns out.

I should mention that the brakes feel great, and the car stops like it never has before after a sensible bedding in period. The brakes have a distinct feel however...probably partly due to the drilled/slotted rotors and the fact that I have never driven on a metallic pad before.

Any help is appreciated.

Thanks.

Boozshey

Well the rear brakes don't work as much as the front. Maybe this is why.

Weed Racer

Uhhh....

Bump.

A_J

Pics would help greatly.. I think I get what you're saying, but I'd want to see it for myself.

A_J

And what kind of rotors and pads?

Also, no offense, butgotta ask, you did use a torque wrench?

Weed Racer

I can't supply pics, sorry, but that shouldn't be necessary anyway.

The pads aren't making full contact with the rotor, but as mentioned, only the outer half of what should be the contact patch.

The bolts were torqued correctly, yes.

The pads and rotors came from a guy in California...Race Concepts, and seemed to be made very nicely.

157dB

Did you bed the pads after installation?
Break them in of sorts?

Weed Racer

Yes I did, and carefully. In fact, I still am since I do mostly highway driving.

The wear pattern or contact pattern on the fronts looked correct after the first 2 mile test drive, but the rears are still not showing contact like they should.

I suppose in time the rear pads will wear in and fully contact the rotors, but who knows how long that will take and what the ramifications will be?

157dB

Did ya rotate the rear pistons back into the
caliper or force them straight in with a C clamp?

A_J

OK - in a perfect world the pads and rotor should be parallel to each other. But from what you describe they're not for some reason or the pads may be binding. Can you estimate how much they may be out of parallel from each other? If it's under 5 degrees as the pads wear they may make up for the angle and eventually wear to match the rotor(I've seen this on passenger cars) - not to say that this is normal, but tolerable. If the pads are contacting at a steeper angle, something is definetely wacky.And the face of the rotors - those are true and flat? And you did also use the torque wrench on your lugnuts? I keep asking about the torque wrench 'cause overtorquing bolts can cause some parts to distort.. also - can you verify that the rear caliper pistons have full travel and not binding?