AFTER TOUCHDOWN ON THE 3,240-FOOT-LONG RUNWAY, THE PILOT EXPERIENCED TOTAL BRAKE FAILURE AND WAS UNABLE TO STOP THE AIRCRAFT BEFORE OVERRUNNING THE RUNWAY. THE AIRPLANE COLLIDED WITH AN AIRPORT BOUNDARY FENCE. FAA AIRWORTHINESS INSPECTORS EXAMINED THE AIRCRAFT AND FOUND THAT THE HYDRAULIC RESERVOIR WAS 3/4 FULL AND THE BRAKE PADS LOOKED NEW. BOTH BRAKE PEDALS WERE SPONGY AND WOULD GO TO THE FLOOR. AIR WAS FOUND IN THE BRAKE LINES. THE BRAKES WERE REPLACED AND SERVICED ON JUNE 23, 1995. THE ACCIDENT FLIGHT WAS THE FIRST ONE SINCE THE WORK ON THE BRAKES WAS ACCOMPLISHED.