Given how much of the rest of the system would have needed to be changed to allow for a larger rotor, I would have been very much surprised to find out that the rotor was the incorrect size. That said, my suspicion is that the brake pads themselves are incorrect.

 

how so? The pads fit the calipers... it's not like I can put another size pad in my caliper.

 

I still have to wonder ("wonder") if for some unknown reason you have 4-cyl calipers (not rotors) and a 6-cyl car?

 

Interesting... never thought of that... I would think the mazda dealership where the rear right caliper was replaced would have been the correct one... even if it wasn't, the rear left is also an issue... hmmm

I've attached images of the car taken after I bought the car 2 years ago (used)... and pictures I took today. Take a look at what I'm talking about.

 

The pads are either wrong, or they're broken. Is the rusting the same on both sides of each rotor and on both sides of the car?

 

why do you say their wrong or broken? The pads fit the caliper in the rear. The caliper won't allow larger pads. Half the rotor stays rusted because the pad only touches half the rotor... I'd like to know the specs on the brakes (pads/rotors/calipers) designed for this car and validate it myself since the mechanics aren't doing anything for me.

 

oh... and to answer your question.. both rear rotors are rusted... whether they are rusted on the inside part of the rotor I do not know... I'll see tomorrow if I can get a good look at it.

 

When I say the pads are "incorrect" what I mean is that just because the pad backing (the metal part) is the correct size to fit the caliper, that in no way means that the friction material is the correct size and shape for the rotor or that it in any way matches the size and shape of the friction material that came from the factory.

When I say "broken" (unlikely given that you're seeing the same pattern on both rear rotors), what I mean is that I've seen the friction material of some brake pads literally break away from the backing and the rest of the material, thus leaving only a portion of the material behind to affect braking.