As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING CRUISE, AN ECAM DISPLAYED FOR A CAUTION HYD Y RSVR LO LVL. COMPLIED WITH EAM AND QRH CHECKLIST. EMERGENCY DECLARED. LANDED WITHOUT INCIDENT. TROUBLESHOT AND FOUND A LEAK AT YELLOW MANIFOLD CHECK VALVE. REPLACED THE O-RING. REPLACED THE NR 2 EDP. OPS CHECKED GOOD.