As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CVG - FLIGHT 3135, THE CREW REPORTED A FUEL LEAK FROM THE RIGHT WING DURING CRUISE. THE AIRCRAFT RETURNED TO IAH WHERE IT LANDED WITHOUT INCIDENT. MAINTENANCE REMOVED AND REPLACED THE FLAPPER CHECK VALVE AT RIB 19 ON THE RIGHT WING. OPERATIONALLY TESTED WITH NO DEFECTS, AND THE AIRCRAFT WAS APPROVED FOR RETURN TO SERVICE.