What was found
ON FLIGHT 4009 THE CREW REPORTED THEY WERE CLEARED FOR AN ILS 27L INTO ORD AND RECEIVED A FLAP FAIL MESSAGE WHEN TRYING TO DEPLOY FLAPS 9, FLAPS STAYED AT 0. THE CREW PERFROMED THE AOM CHECKLIST AND ASKED FOR VECTORS OFF THE APPROACH AND DECLARED AN EMERGENCY. THE CREW RETURNED TO PIT AND LANDED WITHOUT INCIDENT. THE FLAPS NEVER DEPLOYED PAST 0. THE AIRCRAFT WAS REMOVED FROM SERVICE. TROUBLESHOT AND FOUND LEFT NR 3 FSA LEAKING. REMOVED AND REPLACED THE LEFT NR 3 ROOT FLAP ACTUATOR IAW EMB 145 AMM 27-51-10. THE OPERATIONAL CHECK WAS GOOD. THE AIRCRAFT WAS RETURNED TO SERVICE.