I have a 03 Escalade 6.0 liter with hydroboost that is engaging the rear brakes during normal driving, when the pedal is not being depressed. I have done all of the usual work, such as replace calipers and brake hoses. When the usual repairs failed to alleviate my problems I went much further, replacing the ABS module, ABS modulator, master cylinder, rear wheel speed sensors and disconnected the yaw sensor sensor. I am out of ideas and wondering if it is possible for the hydroboost to be causing this problem. Any help would be greatly appreciated!!!!