As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CVG - FLIGHT 3135, ATC NOTIFIED THE CREW THAT FUEL WAS LEAKING FROM THE RIGHT WING, AND FUEL GAUGES CONFIRMED. THE AIRCRAFT RETURNED TO CVG WHERE IT LANDED WITHOUT INCIDENT. MAINTENANCE REMOVED AND REPLACED A LEAKING CHECK (FLAPPER) VALVE ON THE RIGHT WING AT RIB 19, LEAK CHECKED WITH NO DEFECTS NOTED, AND THE AIRCRAFT WAS APPROVED FOR RETURN TO SERVICE.