Ford Repair: hard brakes, no reaction?, engine vacuum, ford taurus

Question
I have a 2001 Ford Taurus SES. The other day my EGR Pressure Feedback Sensor went bad, I have since replaced it. That same day, about 15 minutes later my breaks pretty much quit responding. I can't push my break pedal down barely at all, and the breaks do not respond. What could this be? I have no idea.

Answer
hey there, check to see if the hose that goes to the brake booster is still in tact and attached, this is what give you power brake assist. it must receive engine vacuum. the booster is the round black thing located behind the master cylinder.( where the brake fluid id)
let me know what you see.
good luck
Chris P