As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
RECEIVED 'HYD Y RSVR LO LVL' MESSAGE. DEACTIVATED THE YELLOW HYDRAULIC SYSTEM PER COM PROCEDURES. NOTE: LOSS OF THE YELLOW HYDRAULIC SYSTEM IN CONJUNCTION WITH THE NBR 1 YAW DAMPER BEING INOP PER MEL RESULTED IN ACTIVATION OF ALTERNATE LOW FLIGHT MODE. CONTINUED FLIGHT AND LANDED UNEVENTFULLY. FOUND THE PTU MANIFOLD CHECK VALVE LEAKING. REPLACED SEAL, SERVICED SYSTEM, AND LEAK CHECKED GOOD. AIRCRAFT RETURNED TO SERVICE.