Front Drum Brake Rebuild: Won't Bleed

[wilos]

MY 69 C10 was pulling to the right when braking. The truck is mainly original front drum without power steering. I took the drums apart and found that the drivers front wheel cylinder was leaking. I ordered all new front wheel cylinders and front shoes and rebuilt the brakes.

After getting everything back together I went to bleed the brakes. Since I didn't drain the whole system or touch the backs, I started by only bleeding the fronts. I couldn't get much pedal when bleeding the fronts and the fluid is only slowly coming out of the bleeders on both left and right sides.

Because of this, I tried to bleed the back brakes. When doing this the pedal came back to about half of its normal stiffness. Went to do the fronts again and the pedal went completely away again.

I did adjust the star wheel on the fronts so that the shoes were just rubbing on the drum.

Could it be my master cylinder? If so, would I still get some pedal when doing the rear? Is there something that I am just missing?

Thanks in advance