As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
JFK - CREW REPORTED CENTER HYDRAULIC SYSTEM LOW PRESSURE LIGHT CAME ON IN FLIGHT. NO OTHER INDICATIONS OR FAILURES NOTED. EMERGENCY DECLARED FLIGHT RETURNED JFK LANDED WITHOUT INCIDENT. AIRCRAFT REMOVED FROM SERVICE. REPLACED S-35 CENTER LOW PRESSURE SWITCH. SYSTEM GROUND CHECK NORMAL OPERATION.