What causes grooves on brake rotors? On my rear rotors I can see two grooves on either side but they aren't in the same places on the rotors. I have plenty of pad left too. They aren't making any abnormal noises such as grinding or squeaking either. Thanks in advance fellas.

It can be simply debry getting btwn the pad and rotor. It's normal, nothing to worry about

Could be, but I am thinking this might be more than debris. Each groove is about 1/4" wide if not 3/8". On each rear rotor there are two of these grooves, and each is underneath where the brake pad would travel when the brakes are applied. As I said before, there is plenty of pad left too. There is a definite pattern to the grooves, as they are spaced the same distance apart on either side. The grooves on the passenger side are slightly higher than the drivers side. The grooves aren't very deep either, but clearly enough so that I could feel a depression in the rotor and very visable. I'll get some pictures up tomorrow, its dark here now.

Are you the original owner of the car? Perhaps the previous owner wore the pads down and the underlying metal caused the grooves, which is why you would see a similar pattern on both rotors. Also you might take a wheel off and look at the pads from the inside of the caliper and see if there are any obstructions in there. Do the brakes make any weird noises when you get on em?
-chris b.

No I bought the car with 19,000 miles on it last December. This is something that has happened fairly recently, I regularly check the car over for problems. The car stops fine, and makes no noises so I am not going to worry about it until it warms up a little around here. Im not particularly fond of working sub freezing temperatures.

Tell me about it! It has been freezing nuts up here in Denver. I dont like it at all. 70 on saturday, and then 22 on sunday when I was planning on working on the car... doH!!!

i was also thinking are the grooves lined up with anything on the caliper? Maybe the piston in the caliper isnt putting even pressure on the pad causing one part to rub overly hard? just a long shot...
-Chris b.

Yeah, I live near Boulder so it tends to be a few degrees colder since I am closer to the mountains. But the grooves are under the brake pad... I am just gonna have to take it apart and look at it and see whats up. Thanks for the help fellas!

Actually small rocks or a piece of metal could have gotten in between the pad and the rotor. This will cause it to groove really bad.

I have also seen the stock WRX groove its front rotors with stock pads when they get really hot.

My suggestion is to turn the rotors and sand down the pads to make them smooth, or replace the pads all together.

Or you could just live with it till spring and have to swap the rotors out as well. If you live in cold/wet/winter weather, more sand, rocks and crap will get inbetween the pad/rotor for the rest of the winter.

If it ever warms up or you park your car in a garage, then take your car to a car wash and power spray your brakes with soap/water to clean everything out.

yeah I got the same thing on my back rotors but I did alot of at the limit breaking from 100+ when I actual drove the car so I just figured it was from that lol.

i have groves on my rotors too.

> i have groves on my rotors too.

lol nice... what kind did you go with? oh an are they stock size or did you upgrade to bigger rotors? (i can't tell if you upgraded to rims that'd support bigger rotors)

'95 RS 5spd Red
Black Chrome Matrix Type X CAI
A'pexi N1 Catback Turbo Exhaust
Viper 500esp
Indiglo Gauges
Clear Bumper Lenses
Hiper White Bulbs
Hanabi 9000k HID Kit
Interior Blue LED/Neon Lighting w/ Music Interface
SPAL Deluxe Power Window Kit
Power Trunk Release Kit

i don't remember what kind they are, but they are stock size, can't you tell i still has my sweet ass 14" stockers on?

Have they started to lay sand/salt on the roads up in Colorado? If so may be some of that may have caused the grooves.