I spent some of today working on my mother's brakes. The subject is a 2000 Honda Civic. The problem occurs when you apply pressure to the brakes while traveling over 25mph or so.
I believe the term for what is happening is the brakes are "pulsating". At a certain spot of the rotor-rotation, it forces the brake pedal back up and back down again. Obviously, when traveling quickly it feels much quicker on the pedal, constantly pulsating up and down. Now, I assume it's the rotors because it only happens while braking and I replaced the pads today and it still occurs. The reason I'm asking is because I took the rotors off and they didn't appear warped at all. Also, I'm sure the problem is with the front brakes. Before I buy new rotors, could it be anything else?