The vehicle has drums on all four corners? If so, was the shoes friction material for each ground to the exact circumference of the drum? In other words, does the entire shoe face contact the drum? Reading up on drums brakes from back in the day it is best the shoes entire face contact the entire drum surface for good stopping and good pedal feel. We went through this with a 52 Buick. Bench bled until the cows came home. Bled the cylinders umpteen times. Poor stopping and pedal. Not until the shoes settling in making good contact with the drums did the pedal become firm and stopping ability as it should.