As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING CRUISE, CENTER HYD QUANTITY DECREASED TO ZERO AND SYS PRESSURE AND (RSVR,QTY) LIGHTS ON. EICAS MESSAGE: CENTER HYD SYS PRESSURE AND CENTER HYD QUANTITY DISPLAYED. INFLIGHT EMERGENCY WAS DECLARED PRIOR TO LANDING. UPON INSPECTION FOUND RT WING NR 2 SPOILER POWER CONTROL ACTUATOR FILTER CAP LEAKING. R & R O-RING ON FILTER CAP IAW AMM 27-61-02. SYS OPS CHECKS NORMAL. NO LEAKS NOTED. SERVICED HYD SYS IAW AMM 12-12-01.