What was found
IAH - FLIGHT 2240, THE CREW REPORTED A HYD 1 LOW QUANTITY IN CLIMB. THE AIRCRAFT RETURNED TO IAH WHERE IT LANDED WITHOUT INCIDENT. MAINTENANCE TIGHTENED A LOOSE B-NUT ON THE ELBOW SWIVEL ADAPTER 90 DEGREE BEHIND THE LEFT HYD SERVICE PANEL, SERVICED THE HYDRAULICS, OPERATIONAL; AND LEAK CHECKED WITH NO DEFECTS, AND THE AIRCRAFT WAS APPROVED FOR RETURN TO SERVICE.