Hard to describe as it has only happened a couple of times, but here it goes:
There is a lot of vibration in the pedal and it feels like pressure is released then the pedal has a lot of resistance and will not go down as far as it should (I think). Braking performance seems to be affected as well and there is some noise heard by myself and my passengers.
It only happens if I am coming to a stop and braking hard while driving on a rougher than usual road. It also happened when I was in 4wd in the snow over ice while coming down a slight slope.
I've tried braking hard on a smooth road and everything seems fine.
I'm replacing my calipers, pads, and rotors this week and hopefully that will fix it, but if anyone has some insight into what the problem might be please let me know. Thanks.
It's '99 4runner.