Hi there

I just did a complete brake job on my AWD RX and noticed that on the inside of both rear rotors, the pads were only in contact with 2 strips of rotor, not the entire surface area (see below).

I suspect it's due to a lack of pressure to the rear calipers. The calipers themselves are pretty rusted, but not leaking any fluid or have any other obvious issues. Brake pedal firmness/system pressure seems normal.

I replaced the rotors, pads, lubed pins, and flushed fluid. Rear brakes are definitely being used--they heated up and surface layer of metal on the new rotors began to wear off.

Has anyone seen anything similar? Any recommendations?

 

Are the slide pins frozen?

Did you lubricate them during the brake job?

 

No, Yes.

Calipers seem to work well with new rotors/pads (wear on brand new rotors is visible and even).

I think somehow the rust was allowed to develop, and since then, the middle strip just sanded the pad away when it came into contact.

In either case, there is definitely less pressure on the inside pad than the outside one, probably due to design or some sort of internal wear on my (200k mile) calipers.

 

Do you happen to have pictures of the old pads?

 

Threw them out, but they were flush with the rotor surface, so the center 30-40% was indented inward, corresponding with the rusted area (I think the rust ground off the pad before it was allowed to wear the rust away and bite into metal.