As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ORD - CAPTAIN REPORTED LOST RIGHT HYDRAULIC SYSTEM QUANTITY AND PRESSURE. EMERGENCY DECLARED, RETURNED ORD WITHOUT INCIDENT. AIRCRAFT REMOVED FROM SERVICE. FOUND THE RIGHT HYDRAULIC SYSTEM LATERAL CENTRAL CONTROL ACTUATOR LEAKING AT CAP. REMOVED AND REPLACED O-RING. REMOVED AND REPLACED RIGHT ENGINE CASE DRAIN FILTER AND RIGHT ENGINE DRIVEN HYDRAULIC PUMP. SYSTEM GROUND CHECK NORMAL OPERATION.