Back Brakes won't bleed

If you do as said above by 68gtxman and find that the stoppage is the valve... They can get stuck and it is possible that you jammed it when bleeding. The gunk in the system goes to the bottom of the valve which feeds the rear. That is the most likely place it will get stuck. I know there are posts on here with a procedure to recenter it. I dissasembled and cleaned mine, but that should be a last resort. You can take the bottom cap off and clean it pretty well on the car. There are lots of little parts and springs though...