Intuition tells me that I have a caliper issue, but I wanted to see if it could be something else before I drop the money on that? Car is a 2004 MT with Brembo calipers.

Backstory: I had some fingernail deep scoring/grooving on my front passenger side rotor, so I decided to replace the front with Centric cyro rotors and Brembo ceramic pads. Have been running the new rotors and pads for a few days, and noticed that my front passenger side rotor is marking in the exact same spot as the scoring/grooving on the old rotor. It isn't deep yet, but I imagine continued use will cause it to get deeper. Attached is a photo showing the grooving/scoring on the old rotors. The new rotors aren't that bad yet, however they have a circle in the same exact spot and are only a few days old. Any help is much appreciated.

 

That's odd..


Are you sure you bought the right sized brake pads? Did you install the pads? Did you make sure they were clear of any debris?

Last thought would be to rebuild the caliper.

 

Pads are definitely the right size. Installed them myself. Didn't do the last brake job, but it's odd that the grooving is occurring in the same exact spot.

 

I too think something is getting trapped in there. A brand new pad on a brand new rotor shouldn't be living any marks whatsoever. It's uniform smoothness vs uniform smoothness.

I don't think there is anything wrong with the caliper itself. I can't see why there would be. I would disassemble it and do a quick investigation. Shouldn't take you more than 20 minutes, all said and done

 

Check to see if there's no debris caught in the caliper. Can't see any other way they could groove like this. How do the pistons look? Any of them looks like it could have rubbed??

 

You may have picked something up as soon as you started driving. This isn't the first time I've seen a grooved rotor like that, but it is odd that it happened so fast.

 

I pulled the pads, they look fine. Didn't see any debris or strange markings on the pads. When I put the pads back in and rotate the hub by hand, it is silent for 75% of the turn and makes a very light brushing noise for about 25% of the turn, the sound of the pads grazing the rotors. Is that normal or should it be silent throughout all 360 degrees? Here is a photo of the light grooving I am seeing on the new rotors and pads.

 

I've seen this on random cars and always wondered about the cause.

 

Are you sure this is actually a groove in the making and simply the pads not making contact with the center ring of the rotor (normal by the way)?

 

In the first picture posted both flat head machine screws that hold the rotor in place are missing. In the 2nd picture I noticed you only have a brand new bolt installed, not both. Also the surface where the rotor meets the wheel hub needs to be as flat as possible, free of rust or debris. This will ensure the rotor is balanced properly.

 

Those screws are not even necessary. Once the caliper is placed and the wheel is on, there is no way the disk can move. This is especially true on cars that have the bolts directly on the brake where you just screw the lug nut in. Did the brakes on my moms mini cooper yesterday, for her, she just has holes and the lug nut has the threading so in that case, the mounting screw would help align and keep the pad in place. But those damn screws are torx and even with a impact driver i was not able to take them out. I had to heat the screws with a torch then use impact to get it but 2 out of 4 broke and only the head came out, the rest stayed jammed in. I called Mini to see what my options are and the guy told me just to screw one of the lug nuts in and use a visegrip to apply pressure so the rotor stays firm against the wheel hub. He said once the caliper is on and the wheel is screwed in place, nothing will happen.

As for OPs problem, I would take the caliper and examine it again. There is obviously something that causes that grinding. I don't know if the brembo version have these, but is it possible the pad retainer clip is causing this? I don't see anything sharp that could cause this kind of damage except for the retainer clip

I don't think your problem is the pad rubbing 25% of the way on the rotor because one of the wheels on my moms mini did the same problem. After changing her 4 rotors and pads, I took the car for a spin and for brake-in procedure and the back passenger wheel was also partially rubbing on the disk. It wasn't a constant sound and the faster i was driving, the faster the sound was coming back. When I came back, i took it a part everything looked normal. Although, today it seemed to be better, she drove a few hours while shopping and the more she drove the less the sound was audible. I guess it will disappear soon enough.

 

I always remove those screws holding the rotor in place and throw them in the garbage. I HATE those screws. Never have had an issue without them.

 

Why so much hate? Impact screwdriver and they're off in a second.

 

^^^because bad temper. I agree with you tho.

 

The rotor screws are a factory installed screw to help with speeding up the building of the car. They are 0% necessary when putting on new rotors. I keep them on anyway and I use anti seize on the threads and they come out the next time with a regular screwdriver.