What was found
LOST HYDRAULIC NR 2 FLUID, RUDDER STANDBY POWER OFF, LIGHT ILLUMINATED, LANDED WITHOUT INCIDENT. PERFORMED HYDRAULIC SYSTEM NR 2 FAULT ISOLATION AND TRACED PROBLEM TO NONREVERSIBLE S/O VALVE. REPLACED DEFECTIVE O-RING, SERVICED HYDRAULICS TO PROPER LEVEL. CREW NR 2 SYSTEM EDP DID NOT WORK LONG WITHOUT FLUID, AS PRECAUTIONARY ACTION REMOVED AND REPLACED NR 2 HYD MANIFOLD FILTERS IAW MM. CHECKED EDP CASE DRAIN FILTERS ALL OK. PERFORMED LEAK CHECK, MOTORIZED NR 2 ENG CHECKED FLT SURFACES AND NO LEAKS NOTED. OK FOR SERVICE.