2001 Chevy Malibu - Brake pedal goes to the floor after changing pads and rotors, when car is running.
For the second time, after changing front brake pads and bleeding the system, the brake pedal will press all the way down when the car is running, but will be firm when the engine
is off. The first time, I just pressed the calipers back and thought I had damaged the master cylinder in the process, and replaced a perfectly good master cylinder. I had a friend come over with a pressure bleeder and we bled the system repeatedly. (MC was properly bench bled before installing) The brakes
slowly got better over time.
This time, the brake pedal was firm when we started. I opened the bleeder valves when removing the calipers so I wouldn't force fluid backwards through the system. Replaced pads and rotors. I knew we'd have to bleed the wheel cylinders, and did. Immediately, the same symptom occurs. When the engine is running, the brake pedal can be pushed to the floor with little stopping power.
We did 20 repetitions of hold the brake pedal down, release the bleed valve, close the bleed valve, re-pump the brakes. Again, pedal is very firm when the engine is off.
ABS and BRAKE lights are OFF on the dash.