THE BRAKES LOCKED UP IN TWO DIFFERENT SITUATIONS WHERE I WAS TRAVELING AT APPROXIMATELY 10 MPH. I HAD THE CAR'S BRAKING SYSTEM CHECKED AFTER THE FIRST TIME. I WAS TOLD THE BRAKING SYSTEM LOOKED FINE. THE FIRST INCIDENT I WAS ON THE FREEWAY IN STOP AND GO TRAFFIC. THE SECOND TIME I WAS ON A BRIDGE OVER A HIGHWAY MAKING A LEFT TURN AND WAS TRAVELING ABOUT 10 MPH. BOTH TIMES TRAFFIC STOPPED IN FRONT OF ME AND I APPLIED THE BRAKES AND ALL FOUR WHEELS LOCKED UP AND I SLID INTO THE CARS IN FRONT OF MINE. I HAD NO ABS LIGHT ON THE DASHBOARD AND NO INDICATION MY BRAKES WERE IN DISTRESS.