WHILE DRIVING ON A FREEWAY IN HEAVY TRAFFIC THREE VEHICLES IN FRONT OF ME CAME TO A SUDDEN STOP, TWO OF THEM MOVED TO THE LEFT. I HAD PLENTY OF TIME TO STOP AND WHEN I PRESSED THE BRAKE PEDAL MY BRAKES STARTED WORKING NORMALLY. AS I GOT CLOSER, ABOUT TWO CAR LENGTHS, I LOST BRAKING POWER AND SPED UP AS IF I HAD HIT AN ICY PATCH IN THE ROAD. I WENT TO THE RIGHT AND HIT THE VEHICLE IN FRONT OF ME IN THE RIGHT REAR QUARTER. AT THIS POINT I COASTED TO A STOP ON THE SHOULDER. WHEN I WAS ABLE TO CHECK OUT MY TRUCK I FOUND A LOT OF BRAKE FLUID IN THE RIGHT FRONT WHEEL WELL AREA THAT APPEARED TO HAVE COME FROM THE METAL BRAKE LINE WHICH WAS RUSTY. THE TRUCK WAS SO HEAVILY DAMAGED I COULD NOT GET A PICTURE OR SEE THE HOLE IN THE LINE. THE AIR BAGS DID NOT GO OFF. THE TRUCK WAS TOTALED. *TR