Chevrolet Repair: Rear brakes, chev blazer, brake calipers

Question
I just replaced both sides of the rear brake calipers, pads on a 2003 Chev. Blazer 4x4. After bleeding the brake lines and have a steady stream from both sides the brake pedal still goes to the floor. With the igition off the brake pedal will stay about 1/2 way down and is hard. Start the Blazer and the pedal goes to the floorboard. Any clue what I did wrong or is there something else wrong with the brake system?

Answer
This truck is an ABS truck.  There's a totally different bleed procedure that can only be done at the dealer with the TECH 2 scan tool.  This is most likely the problem.  It is an automated bleed procedure, that with the help on the scan tool, can get the air out of the ABS module, unfortunately this is the only way to do it.
Jimmy