89 735i brakes self apply when warmed up. help!!!

Hello everyone. I recently purchased a 735i and have had a major issue with the brakes. It seems that after driving the car for about 20-30 min the brakes start to self apply. Its gradual, but will get to the point of smoking the brakes! It got so hot that it melted the grease out of the front hubs! I have replaced the front hubs, rotors, pads, n calipers and blead the system. pulling my hair out and starting to regret buying the car. need help fast!