Firm brake pedal, but no fluid to rear calipers.

I recently replaced the brake lines on my 2002 Silverado. I replaced the lines from the front wheels to the ABS modulator, and the 2 lines from the master to the ABS modulator. Line to the rear was untouched. Front calipers bled perfectly and the pedal is firm. The rear calipers however are not getting any fluid. It acts like someone has clamped off the rear brakes. Pedal is perfect but no fluid to rear. Lines on the ABS modulator are connected correctly. If there is air in the line wouldnt the pedal go soft... Any suggestions would be appreciated... Thanks