Rep Power: 0

I got my rear drums swapped to disc and the other day I went out to test the brakes out. After several 60-10 and 80-20 stops my brakes were smoking. Today I noticed the front right discs has two grooves going all the way around. I know discs should be flat, so this is bad.

My question is what could have caused this grooving to occur? I'm going to change that disc and install new pads. But I don't want it to happen again.

 
Rep Power: 811

maybe some debris or rocks got stuck inside?

 
Rep Power: 388

The groves are on your orig front discs correct- if so, could be caused from running your breaks down beyond their useful life, or debris as gear said. Two small groves arent going to hurt performance to any noticeable degree. I've seen rotors that are much older and they were completly groved- thats what you want to avoid. For the most part, if you change your break pads regularly, your still going to end up with some small groves on your rotors. Run your fingernail across the surface, if you have a lot of groves that are close to gether, replace them.

OLD (needs to be replaced) VS NEW rotor.

 
Rep Power: 0

yep, sounds like your rotors are gone. You'll proly want new pads too because the rotor proly ruined those too

 
Rep Power: 272

the rotor on the left looks like my **** right now LOL