2001 dodge ram 1500 brakes

I have a 01 dodge ram 1500 brakes started going
to the floor I replaced the rear wheel cylinders and
brake lines going into the cylinders now  when I go
to bleed the brakes I'm getting no fluid coming out
of the rear wheels I have seen a lot of things online
talking about bleeding the master cylinder but I'm
not sure how to do this and then I saw something
about bleeding the ABS system with a scan tool
which I have but everything I see says if there's no
fluid going to the wheels then that is not the time
to do the Abs but the master cylinder