As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) LOSS OF NR 1 HYDRAULIC QUANTITY AND PRESSURE IN CRUISE.ON ARRIVAL MAINTENANCE PERSONNEL FOUND THE HYD NR 1 TANK EMPTY AND A VISUAL INSPECTION AT THE UNDER WING AREA SHOWED HYDRAULIC FLUID LEAKAGE FROM THE BALANCED RELIEF VALVE DRAIN TUBE.