Since about 40,000 miles ago, my brakes have been pulsating in the car. Because of this, I've replaced the rear rotors and pads but it didn't help. Whenever I come to a stop, the pulsation rate slows down as the car's wheels slow. In short, the pulsation is dependent on front wheel speed.
Today, I replaced both the front rotors and pads. Upon spinning the rotor freely by hand with the caliper installed, to my surprise, I hear the pulsation. On one side of the rotor, I hear the scraping of pad to rotor contact, once the rotor turns 180 degrees, the pad isn't touching the rotor and it spins freely. So it sounds like shhh-silence-shhh-silence-shhh-silence, etc. I have cleaned the wheel hubs very well before installing the rotor and they don't have any hints of rust. They're still shiny. If I look at the rotor while its spinning, I can see the outer edge moving a little bit as it turns but only very slightly.
My car has 244600 miles.
You may have a bent rotor hub. This can be checked with a dial indicator gage and if hub is bent more than 10 thousands of an inch it will cause the rotor to move back and forth and cause pulsation.
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