As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
MIA - CREW REPORTED LEFT HYDRAULIC SYSTEM QUANTITY DECREASE. EMERGENCY DECLARED, RETURNED MIA LANDED WITHOUT INCIDENT. AIRCRAFT REMOVED FROM SERVICE. REPLACED THE AUTO PILOT SERVO HYDRAULIC PRESSURE LINE AND THE UNION AND PACKING. SYSTEM GROUND CHECKED NORMAL OPERATION.