Abs breaks modulator issues

[Joe B]

I have a 2004 Avalanche 1500 5.3L  V8 4x4 Z71  with tow Package  my brake lines were rusted  replaced all the lines  to the ABS module  bleed the lines but only getting pressure in one cylinder & power is going to the motor module  is the modulator clogged or need to be replaced when  bleeding the lines there was very little fluid coming out of them & tried to go in by  computer to have the pump bleed the lines it blocked me out ? what is causing this problem to not get equal pressure to my wheel cylinders!