Brakes problem
1998 Jeep Cherokee 6 cyl Four Wheel Drive Automatic 140000 miles

I replaced all the brakes, front/rear with new rotors, calipers, pads and hardware. I even replaced the rear emergency brakes (mechanical, inside the rear rotors). I cannot get the brake pedal to come up bleeding out the system. I have bled the system several times beginning with the proportioning valve, ABS block (all lines) (had the key on), then all wheel cylinders starting at the R rear and progressing forward away from the master cylinder. I cannot get a pedal back up after bleeding. Pedal goes to the floor and it will pump up (approx. 7-8) to get a pedal, but as soon as pressure comes down, pedal goes back to flloor. I do not have a pressure bleeder and I am just having someone work the pedal as I bleed. I have done this many times and never had this occur. Any help is very appreciated. Thanks, Bill