Just bought a 2001 7.3 excursion a month ago. Always wanted one. I have read hours of posts but can't find my issue. When applying the brakes the pedal seems fine at first but the fades almost to the floor. It takes a long time to return but applying them a few seconds later when it finally returns gets me a firmer pedal and good stopping with no fade. I am a mechanic with 28 years of experience but next to none with diesel or hydro boost. First thought is air as the second pump is firm. But the extremely slow return of the pedal, which prevents a quick second pump, has me waffled. I have newer calipers and brakes and rotors. Inhale bled them manually rr-lr-rf-lf. No air and no improvement. Any help would be greatly appreciated!!