As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CREW REPORTED CTR HYD SYS QTY LOSS. EMER DECLARED FLIGHT RETURNED & LANDED WITHOUT INCIDENT. ACFT REMOVED FROM SERVICE. REPLACED O RING AT C2 ALTERNATING CURRENT MOTOR PUMP FILTER MODULE OUTERMOST PRESS LINE. SYS GND CHECKED NORMAL OPERATION CLOSED.