it started as routine maintenance....

[cdfg]

98 Contour SE

But of course, now it's much more complicated. ok, changed the front pads and turned the rotors, all well and good, but now the stupid thing won't hold a vacuum when the car is turned on. I can push the pedal all the way to the floor. bled the system about 4 times (actually 4 times for sure). check the vacuum booster hose and non-return valve. any other suggestions? or tricks for bleeding that I may have missed?

Also, can't get the dang non-return valve back into the intake manifold, thus can't start the car now! Help!