rotor wear

[mbaker]

What causes circular grooving around rotors? Is it hard spots in the pads or weak spots in the rotors or both?

2 scenarios:
I have a 07 Honda odyssey that at 190k I finally had to replace the front rotors and put on Oreilly's brake best rotors with Honda pads. now with 250k those rotors are still flat as new as the pads are nearing replacement again. I actually expected these to wear faster and more uneven than the OEM rotors, but to my surprise they have not and outside of being darker from pad material show litte noticeable wear.

I also have a 06 Buick, it has Oreilly brake best select rotors and ceramic pads on the front and after 50-60k, the rotors have grooves like a record worn around them. There is still pad left, but its starting to pulse so they will be getting swapped soon.

Since both vehicles are the same rotor line, I am guessing this is a pad issue related to the brake best line? I've wondered if the ceramic formula isn't as evenly mixed and leads to hard spots in the pad?

I am switching the Buick to Raybestos element 3 pads and rotors to see what happens both front and rear. Typically Ive ran oreilly or advance pads premium pads because when I needed them I needed them in a hurry and for the most part haven't had problems with brake function just curious why they wear like this.

 

[Pew]

Uneven deposits from the pad onto the rotor face that harden when cooled will start the grooves.

 

[930.engineering]

What causes circular grooving around rotors?
Is it hard spots in the pads or weak spots in the rotors or both?

The first is possible but less likely. The latter is impossible.
Much more likely is it picked up a tiny stone.
.

 

[mbaker]

The first is possible but less likely. The latter is impossible.
Much more likely is it picked up a tiny stone.
.

 

[mbaker]

It’s consistent on both rotors and isn’t just a single groove is ‘wavy’all across the contact area both sides of the rotor. That makes me think it’s just a wear characteristic of that combo and not a single stone or other impurity getting embedded. I guess I’ll find out if the Raybestos act the same way.

The rear was still factory pads and rotor as far as I could tell at 120k. ( I’ve had it since 45k) Maybe the front is really abused in these cars and since they have worn down twice as fast, it’s just harder on the pad and rotor combo.

 

[benjy]

quality varies a LOT these days with many parts from many places, basically its a crap shoot IMO!!