What was found
EWR - FLT 0261 - THE GREEN SYSTEM HYDRAULIC FLUID QUANTITY DROPPED TO 1.3 GALLONS WHILE IN-FLIGHT AND WAS ACCOMPANIED BY ILLUMINATION OF WARNING LIGHT. THE HYDRAULIC LOSS CHECKLIST WAS COMPLIED WITH AND THE AIRCRAFT LANDED WITHOUT INCIDENT. MAINTENANCE FOUND THE FLAP INSTRUMENTATION UNIT TIMING VALVE HYDRAULIC LINE LOOSE AT THE B-NUT. THE B-NUT WAS TIGHTENED AND THE GREEN HYDRAULIC SYSTEM WAS SERVICED. THE NR 2 ENGINE WAS RUN AND ALL FLIGHT CONTROLS WERE CYCLED WITH NO LEAKS NOTED. (X)