When I am coming down from about 65 to 50 my brakes begin to chugg and the vehicle shakes a little but once i'm in the 20 to 30 range the vehicle is fine and I can come to a complete stop normally with the exception of some times when coming to a complete stop the vehicle chuggs. I was wondering what could be causing this, I just changed the oil and got new tires, I know the vehicles needs a tire rotation and an alignment but and I plan to change out the power steering and brake fluid. Any idea what my problem cou