As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ON APPROACH, 'A' SYSTEM HYDRAULIC QUANTITY WENT TO ZERO. HOWEVER, PRESSURE ON 'A' SYSTEM REMAINED GOOD. CREW DECLARED AN EMERGENCY AND LANDED IN PHL WITHOUT INCIDENT. MAINTENANCE FOUND A LEAK IN THE ELEVATOR PCU FILTER HOUSING. REPLACED FILTER HOUSING, OPERATIONAL CHECK OK.