We have done a great deal of work to my cars brakes, but the pedal still travels way to far before it stops.?

Could be in the brake booster, or in the brake equalizer. There is a unit in the brake system that differentiates the pressure between front and back brakes to apply appropriate pressure to each caliper and brake cylinder. This can be malfunctioning or need to be adjusted. This unit is just down the line from the master cylinder in the brake lines.