As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE A-SYSTEM HYDRAULIC FLUID QUANTITY DROPPED TO ZERO ACCOMPANIED BY ILLUMINATION OF LOW PRESSURE LIGHT WHILE AT CRUISE. THE AIRCRAFT WAS RETURNED TO EWR WHERE IT LANDED WITHOUT INCIDENT. MAINTENANCE FOUND THE NR 2 ENGINE DRIVEN HYDRAULIC PUMP SUPPLY LINE LEAKING. THE SUPPLY LINE WAS REMOVED AND REPLACED, LEAK CHECKS WERE GOOD.