What was found
NON-ETOPS FLIGHT 88 HNL-KOA, DURING TAKEOFF, THE CREW NOTED THE HYDRAULIC QUANTITY DROP FROM 3 GALLONS TO LESS THAN 1 GALLON. THE CREW ELECTED TO ABORT THE TAKEOFF AT LESS THAN 80 KNOTS INDICATED AIRSPEED. MAINTENANCE FIRST REPLACED A LEAKING O-RING SEAL ON THE A SYSTEM BRAKE AUGMENTATION VALVE AND SERVICED THE HYDRAULIC RESERVOIR. MAINTENANCE THEN DECIDED TO REMOVE AND REPLACE THE BRAKE FEEL AUGMENTATION VALVE PER AMM 32-41-00 WITH ALL OPERATIONAL AND LEAK CHECKS SATISFACTORY. THE AIRCRAFT WAS RETURNED TO SERVICE.