What was found
AFTER ENGINE START, CREW HAD A NORMAL HYD FLUID QUANTITY OF 56%. ON CLIMB OUT AT AROUND 33,000 FT NOTICED QUANTITY AROUND 28%. AFTER A FEW MINUTES, QTY HAD SLOWLY DROPPED TO 25%. CREW DIVERTED TO CVG, RAN ALL NORMAL CHECKLISTS. ON BASE TO FINAL, CREW RECEIVED A FLAPS FAIL MESSAGE PRIOR TO USING FLAPS. RAN CHECKLIST & ABLE TO GET FLAPS TO RESET & LANDED UNEVENTFULLY. AN EMERGENCY WAS DECLARED BY ATC. NO LOW HYD FLUID CAS MESSAGE WAS EVER POSTED WHICH NORMAL OCCURS AT 16% QTY. CREW SHOWED 20% REMAINING AT TOUCH DOWN IN CVG. TECHNICIANS FOUND THE RT HYD EDP PULSATION DAMPER O-RING LEAKING. O-RING & BACKUP RING REPLACED, LEAK CHECKS PERFORMED, AND THE AIRCRAFT WAS RETURNED TO SERVICE.