WITH PARKING BRAKE FULLY SET TO THE FLOOR, TRUCK ROLLED DOWN BOAT LAUNCH SMASHING BOAT TRAILER INTO DOCK. WITH PARKING BRAKE COMPLETELY SET TO FLOOR, ON LEVEL GROUND, DRIVER ACCIDENTLY LEFT VEHICLE IN DRIVE AND EXITED WITH MOTOR RUNNING. TRUCK ROLLED FORWARD NEARLY RUNNING OVER DRIVER. PARKING BRAKE WILL NOT HOLD VEHICLE WITH MAXIMUM RATED GVWR, WILL NOT HOLD ON INCLINE, AND WILL NOT HOLD WHEN TRUCK IS LEFT IN GEAR. EXCESSIVE PEDAL EFFORT IS REQUIRED TO GET BRAKE TO WORK AT ALL. SEVERAL OTHER OWNERS HAVE HAD SIMILAR PROBLEMS. FORD SAYS "CHARACTERISTIC OF VEHICLE". *AK