Hi, I recently replaced 4 rotors / calipers / pads on my '99 silverado. I bled the system, but noticed that there was no pressure and the pedal was traveling to the floor with minimal braking. So we replaced the master cylinder, bench bleed it, and now have brakes. The old MC was original, 110,000 miles. But here is the problem, we've bled the system multiple times, from MC, each wheel, and the pedal is still spongy. Also, the brake pedal seems to have developed a 'binding' noise coming from the brake booster when depressed. Could the brake booster be failing and causing these problems? Or I've been reading that the rubber brake lines could be causing the problem. I found this video on youtube. This is the EXACT same thing that is happening with my pedal. http://www.youtube.com/watch?v=dwVHP2WWPmw&feature=related Any input would be appreciated. thank you.