TL*THE CONTACT OWNS A 2000 CHEVROLET SILVERADO 1500. WHILE DRIVING AT LOW SPEEDS AND THEN DEPRESSING THE BRAKE PEDAL, THE PEDAL VIBRATES AND PUSHES BACK ON THE CONTACT'S FOOT. HE FURTHER STATED THAT THE PEDAL EXTENDED TO THE FLOOR WHEN THE BRAKE PEDAL WAS DEPRESSED, BUT THE VEHICLE DID NOT SLOW DOWN OR STOP. THE CONTACT CONTINUED TO APPLY PRESSURE TO THE BRAKE PEDAL, BUT NOTHING HAPPENED. THE CONTACT HAD TO CRASH INTO A PILE OF COD TO STOP THE VEHICLE. THE CURRENT MILEAGE WAS 77,100 AND FAILURE MILEAGE WAS 66,300.