As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED: YELLOW HYDRAULIC SYSTEM FAILURE WAS REPORTED, AN EMERGENCY WAS DECLARED AND THE AIRCRAFT RETURNED TO PHL WHERE IT LANDED SAFELY WITHOUT FURTHER INCIDENT. MAINTENANCE FOUND THE #2 ENGINE DRIVEN HYDRAULIC PUMP PRESSURE HOSE CHAFFED THROUGH AT CLAMP AND LEAKING. REPLACED HOSE AND ACCOMPLISHED A SATISFACTORY LEAK / OPERATIONAL CHECK PER AMM 29-13-51.