Well, I got the drum and wheel cylinder warranty replaced from the
autoparts store where I got them a month ago, and bought new brake shoes
and springs to go with them. Also ordered(will be here tomorrow) a new
rear brake hose, the rubber line only.

I disconnected the hose from the wheel cylinder and had someone push the
brake with it this way. Barely any fluid came out. Just dribbled a
little. Then I disconnected the hose from the metal brake line and had
them hit the brake again. This time fluid shot out of the line like a
fire hose. I reconnected the rubber line back up and repeated the test
and the fluid just dribbled.

So I concluded that the rubber hose is collapsing internally, or is
clogged. Either way, I'm getting a new one and will post back if this
fixes it or not.

Only thing left to replace would be the adjuster, and it seems to be
working fine. Otherwise, I could run a new metal line all the way back
from the master cylinder. The line looks fine though and fluid flows
freely through it. I don't think it's that at all.