What was found
AIRCRAFT WAS GROUNDED: AN EMERGENCY WAS DECLARED UPON LANDING AT TO ORD DUE TO THE FLIGHT CREW REPORTING SMOKE FROM THE NOSE LANDING GEAR - MAINTENANCE FOUND THE GREEN HYDAULIC SYSTEM HAD EMPTIED ON LANDING AND TOWED THE AIRCRAFT TO THE GATE - MAINTENANCE FOUND A LOOSE B-NUT WHICH WAS LEAKING HYDRAULIC FLUID FROM THE NOSE WHEEL STEERING SERVO CONTROL VALVE AND SECURED THE B-NUT - A SATISFACTORY OPERATIONAL CHECK WAS ACCOMPLISHED WITH NO ISSUES NOTED