You may have a faulty master cylinder that is not pushing the fluid, also the ABS module needs to be bled first then start at the furthest point, hence passenger rear and ect..also check for a crimped line, some times rubber lines will deteriorate and not let fluid through..
After all this, what have you done to the rear brakes that requires bleeding? Tell me exactly how you are trying to bleed the brakes! It's simply bleeding brakes, just like you always have! Need more info. on your procedure.