As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE LEFT ENGINE HYDRAULIC PRESSURE DROPPED TO ZERO SHORTLY AFTER TAKEOFF. THE HYDRAULIC QUANTITY WAS NORMAL. THE AIRCRAFT WAS RETURNED TO EWR WHERE IT LANDED WITHOUT INCIDENT. MAINTENANCE FOUND THE LT ENGINE DRIVEN HYDRAULIC PUMP HAD FAILED DUE TO A WORN SHAFT. THE HYDRAULIC PUMP WAS REMOVED AND REPLACED. THE ENGINE WAS RUN AND LEAK AND OPERATIONAL CHECKS WERE GOOD.