1999 GMC SIERRA PICKUP REGULAR CAB 4 WHEEL DISC BRAKES. TRUCK WOULD NOT COME TO A COMPLETE STOP AT A TRAFFIC LIGHT, SPEED LESS THAN 5 MPH. PEDAL VIBRATED THEN WENT ALMOST TO THE FLOOR. TRUCK BUMPED INTO CAR IN FRONT OF IT CAUSING MINOR DAMAGE TO CAR, VERY SLIGHT DAMAGE TO TRUCK. ROADS WERE CLEAR AND DRY, DAY WAS COLD BUT SUNNY. *TR