silly question

i just got done swapping over to BBP and disc brakes. and for the life of me i cant get the rears to bleed. now im probillay going to answer my question. did i need to grab the rod that attaches to the brake petal and goes inside the master cylinder, cause i can get fluid coming out of the rear part of the cylinder and fluid coming out of the disc up front but when i crack the front part of the cylinder nothing not even at the wheel cylinders out back. it also seems to be making a slirshing sound from inside the cylinder when trying to pump them up. do i need to grab that rod too?