Marks on Rotors
 

Yesterday I just gave my car a rinse to get rid of the pollen on it, parked the car and didn't drive it for the rest of the day. When I went to work this morning, when I first started backing out of my garage I heard/felt a clunk from mostly the rear. My brakes were also making rubbing/grinding noises when the pedal was pressed on the way to work.

Now I know when rotors get wet they develop surface rust, but I've never experienced it like that before. It rained today while at work, and they made the same noise on the way back. Anyways, once I got home from work I took a look at my rotors and found this:

https://c1.staticflickr.com/3/2904/3...4348fbf8_c.jpg

https://c1.staticflickr.com/4/3951/3...0058b467_c.jpg

Each rotor has a spot like this on them where you can see a mark left by the pads. Anyone know if this will wear off or are my rotors fubared? I'm not terribly familiar with brakes

It will wear off I am sure but in many years of rotor manufacturing and seeing 100s of warranty returns I have never seen anything like that before.


How far did you drive after the rain?

I live about 7 minutes from work so not far. I've only had these pads for 2 months but they've never given me any issues whatsoever before. Maybe enough surface rust on the rotor to make contact with the pad surface?

Braking feels completely normal minus a tiny bit of a gravely feeling, although the road I drive on is fairly rough and could be my mind overanalyzing.

Ya surface rust means nothing and will not be an issue. I find the difference in the surface between the mark and the rest of the rotor interesting though. Seen lots of pad marks before but they usually disappear after just a couple of applications of the brakes. I will show that to one of the quality guys tomorrow and see what he says. Could be perfectly normal and I have just missed seeing it. As long as they are working OK I wouldn't worry about them.

Looks rather like it sat in one place for several days in a row getting wet and drying out for a number of cycles.
Do you park near any sprinklers?

Thanks, I'm interested to see what he says!

Not near any sprinklers, but it sat for probably 16 hours right after getting a quick rinse.

I had the same exact thing happen to mine after i washed my car, went away after some miles

you need to brake harder.

I'm not kidding. Things like this stay around when you use the brakes lightly.

7 minutes of driving is not sufficient distance to rub off that brake pad mark.


Put something heavy in the trunk and drive longer faster harder. I am sure those pad marks will be rubbed off.


Always drive your car around right after finishing the wash to avoid this problem, along with other moisture collection in the hidden area.

Drive your car after you wash it to dry the water off the rotors.

OK so I talked to our engineers and as everybody has said it is normal pad marks from being wet. They were also baffled at first since the pics seemed to show excessive pitting and different wear marks than the rest of the rotor. We threw the pic up on a different computer and the marks don't look near as bad as they did on my monitor.
Give it a good drive and some moderate brake pressure and all is good.

This is similar to people that bed brake pads. Two types of people:

1) those that "brake hard" and complain about noise, lack of bite, or something else.
2) those that know how to bed brakes, and make the pads smoke when they are first bedded.

By "braking hard" I really mean you need to find an empty stretch of road and do a complete full stop from around 50MPH so you can get enough rotations on the rotor in with full pressure contact on the pads.

Good to know! I'm gonna basically do a bedding procedure later today and see if it helps get some of it off. Thanks!!

Pad marks from sitting wet, normal.