What was found
DURING CRUISE PHASE OF FLIGHT. THE AIRCRAFT DISPLAYED THE FAILURE MESSAGE FOR HYD Y RSVR LO LVL, DUE THAT SITUATION THE PILOT RETURNED TO DEPARTURE FOR MAINTENANCE. UNEVENTFUL LANDING, MAINTENANCE PERSONNEL PERFORMED FAULT ANALYSIS IAW TSM 29-13-00-810-801-A, VISUALLY CHECKED THE HYDRAULIC FLUID LEVEL IN THE YELLOW HYDRAULIC SYSTEM RESERVOIR, FOUND NORMAL QUANTITY INDICATION, DETERMINED THAT IT IS A FAILURE OF THE INDICATION SYSTEM. THE AIRCRAFT WAS RETURNED TO SERVICE.