What was found
NON ETOPS FLT 71 HNL-LIH. WHILE TAXIING PRIOR TO TAKEOFF, CREW NOTED A SYSTEM HYDRAULIC FAILURE. CREW NOTIFIED TOWER AND WAS TOWED BACK TO HANGAR BY MAINTENANCE WITHOUT FURTHER INCIDENT. MAINTENANCE FOUND A PACKING ON THE NR 6 FLIGHT SPOILER ACTUATOR PROTRUDING. MAINTENANCE REPLACED THE PACKINGS FOR BOTH CAPS ON THE SPOILER ACTUATOR HOUSING AND INSPECTED BOTH NR 1 AND NR 2 ENGINE CASE DRAIN FILTERS. THE HYDRAULIC SYSTEM WAS SERVICED AND A LEAK AND OPERATIONAL CHECK WAS PERFORMED. AIRCRAFT WAS RETURNED TO SERVICE. LATER THAT NIGHT, NR 6 SPOILER ACTUATOR WAS REPLACED AS A PRECAUTION. AIRCRAFT RETURNED TO SERVICE.