hate to see folks jump to dumping good rotors if not needed. Of course, the brake system is fiddly enough that it's always good to inspect it. Things must be able to move evenly and center themselves under hydraulic force, but also release and float when not used.
I have cured brake pulsing in 3 cars by left-foot dragging. Daughter's car took a second, more aggressive attempt. I did the wife's 03 once. Worked fine. If I'm not hard-driving on my WRX often enough, it will get a little uneven feeling and the technique brings it back to smooth for me. Could be the StopTech pads are different enough that they need aggressive use more regularly. That seems to be everyone's theory about them and my limited experience confirms it. (man, after I do the technique on my WRX, it really bites and modulates smoothly!)
It's easy to try and safe - IF you select your road carefully, and make sure to do the cool-down run with no stops. You don't want to clamp hot pads onto a hot rotor. That's how 90% of the uneven pad material transfer issues start. An emergency-type stop followed by sitting at a light or RR crossing w'ever with hot pads in one spot on the rotor. If you MUST stop of course, do w'ever you need to to be safe. If possible, use the hand brake to hold the car at a light. (works on Subarus with the little drum/hat parking brake shoes - won't work if the p-brake use the regular pads)
On my daughter's Impala, I could SEE the outline of a pad on the rotor through the wheels!
I have a low-use highway service road near where I live that I can easily cruise down on a weekend morning to check for activity/cops. Then come back through and do any brake bedding-in or other runs I might need to do. Again, doesn't really take long and, if there's no sign of improvement or the problem gets worse, you probably need new rotors. I have read that under extreme condistions of overheating, the rotor alloy under the pad can alter to 'cementite' and the change goes far enough under the surface that even a lathe may not remove all of it. Modern brake rotors may only have a millimeter you can take off each side. I'd replace it instead of cutting it deeper than the minimum thickness - or maybe even getting 'close'.
Edited by 1 Lucky Texan, 18 October 2017 - 10:45 AM.