2012 Ford edge with 175K miles. Brakes begin to engage lke normal at a slight tap of the pedal (slight braking action), but to bring the car to a stop you need to essentially push the pedal to the floor. So, some resistance at the top of the stroke, then nothing, then the car will stop when the pedal hits the floor.

I bled the brakes 2x, then I had a shop bleed the brakes. No improvement.

How would you go about tackling this one? I realize it could be a number of issues, but I want to troubleshoot in the right order.