APPROXIMATELY ONE WEEK AGO WHEN DRIVING I APPLIED THE BRAKES AND HAD VERY LITTLE EFFECTIVENESS DURING A STOP IN SLOW SPEED TRAFFIC. INSTINCTIVELY I KEPT PRESSING THE PEDAL DOWN HARDER WITH NO IMPROVEMENT. DID NOT HIT ANYTHING BUT WAS SHAKEN UP. I BLEW IT OFF THINKING I BRAKED TOO LATE. ON 1/26/2013 WHILE DRIVING ON THE HIGHWAY DURING LOW SPEED TRAFFIC AGAIN SAME INCIDENT OCCURRED. TRAFFIC WAS HEAVY AND WE WERE ROLLING ABOUT 15 MPH. BRAKES DID NOT RESPOND EFFECTIVELY, CAUGHT MY ATTENTION AND PUSHED VERY HARD. PLENTY OF ROOM IN FRONT THOUGH TO SOMEWHAT COAST-BRAKE TO A STOP. LESS THEN 30 SECONDS LATER, TRAFFIC STILL STOP AND GO, WITH PLENTY OF ROOM TO BRAKE I PUSHED ON BRAKE PEDAL WITH NO BRAKING. PUSHED THE PEDAL AS HARD AS POSSIBLE- NOTHING- AND COASTED INTO THE REAR END OF CAR IN FRONT OF ME. LOW SPEED IMPACT WITH MINOR DAMAGE TO CAR IN FRONT. FRONT BUMPER, GRILL AND RADIATOR DAMAGE TO MY CAR. THANKFUL IT WAS NOT DURING HIGH SPEED DRIVING. DID SOME RESEARCH ON INTERNET TO FIND IT HAS BEEN HAPPENING IN THE HYBRID VEHICLES WITH THE "HYDRAULIC CONTROL UNIT" SOMETIMES NOT FUNCTIONING. TAKING CAR TO DEALERS TO DROP IT OFF FOR COLLISION ESTIMATE AND HAVE THEM LOOK INTO BRAKING SYSTEM. APPROXIMATE COST REPAIR ACCORDING TO OTHER REPORTS ABOUT THIS PROBLEM IS $4,000.I FEEL VERY UNSURE ABOUT DRIVING THIS VEHICLE AGAIN ONCE IT IS FIXED AND IF PROBLEM CAN BE IDENTIFIED. AND IF FORD CAN NOT FIND THE PROBLEM WHERE DO I GO WITH IT? NUMEROUS COMPLAINTS FROM OWNERS IN REPORTS I READ LAST N