I am trying to figure out how my pads and rotors have worn this way (see attached). It is the same on both front tires. The outer third of the inside brake pad has a groove worn in it. You can see in the side-profile photo that the pad is wearing normally in the inside 2/3, and can see that it is contacting the rotor at that point. The rotor has rust buildup on the outside 1/3, and the groove in the pad is going around it. Does anyone know what can cause this type of wear? Thanks!

 

You are talking about a vehicle that is 8-9 years old at this point, with no telling what kind of conditions it has been run in for that amount of time. My first idea is that the caliper bushings have started to bind, or that the pistons have started to get sticky in the bores.

Front calipers have a service life, and at about every second pad change. the calipers pretty much need to be rebuilt / replaced, which eliminates them as a source of problem, which might be the case here.

Your pictures aren't with the post.

 

Pics are now attached. FYI this is the first time the pads/rotors have been replaced. 97,xxx miles. The calipers are one of the things I considered may be worn out. Thanks

 

rusted old rotors and lack of brake service. replace your pads and rotors and perform a brake service.

the caliper brackets must be cleaned or the pads will bind in the brackets, calipers pins must be lubricated with silicon brake lubricant or the floating calipers will not slide.

 

I have since replaced the pads and rotors. I did not think to lubricate the caliper pins. I'll go back and do that. Thanks!