As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING FLIGHT THERE WAS A SUDDEN LOSS OF NR 4 HYDRAULIC QUANTITY WHICH RESULTED IN A LOSS OF PRESSURE AND QUANTITY WENT TO ZERO. FLIGHT CONTINUED ON AND LANDING WAS UNEVENTFUL. ALTERNATE GEAR AND FLAP SYSTEMS WERE USED. MAINTENANCE FOUND NR 4 ENGINE DRIVEN HYDRAULIC PUMP LEAKING. REMOVED AND REPLACED NR 4 ENGINE DRIVEN HYDRAULIC PUMP AND RESET ALTERNATE SYSTEM FOR GEAR AND FLAPS. OPERATIONAL CHECKED GOOD AND AIRCRAFT WAS RETURNED TO SERVICE.