disc/drum diagnosis help needed

[1] You should fit auto adjusters to the rear drums. They work & keep the pedal high.
[2] If you have a low pedal, but the pedal is hard, & you cannot pump up the pedal, that suggests an internal problem in the m/cyl. The m/c is probably made out of Detroit's wonder metal, cast iron. They rust. The seals get pushed over rusted sections as pedal travel increases & this can damage the seals, cause internal leaks.