I need a BRAKE edu-muh-cation

[BA.]

I've got a pedal that always goes to the floor! It doesn't pump up. :(

I bought this old Jeep Cherokee recently to use as a winter vehicle.
The brakes on it were horrible, and mostly original looking so I knew a full brake overhaul was in order.


So, I've replaced the Calipers/pads/rotors. There were never any leaks of any sort, the Master cylinder does not leak, hoses all look good, hard lines look good.

I bled the brakes yesterday, front only, but used a method I had only read about previously.

I loosened the bleed-screw and put a rubber hose on it with the other end deep into a container of brake fluid. Supposed to prevent air from getting sucked back up the hose.

So, I get in the jeep and proceed to pump away and sure enough, fluid is leaving the Mstr Cyl and going into the container. I top the MC off, tighten up the bleed-screw and think I'm done.
I repeat for the other side and STILL my pedal goes to the floor.
WTH?
Could a bad Mstr Cyl. cause this, even though it's not leaking anything?
My only other plan is to do a traditional bleeding once I get a helper to pump the brakes.

One other detail, the rear drum cylinders leak so at this point that part of the Mstr Cyl. is empty. I didn't think that would affect my front brake work/function.

Help!