What was found
DURING CRUISE, THE HYD 3 PRESSURE HIGH ALERT. HYD 3 OFF. TEMP WENT TO 120 DEGREE C AND PRESS TO 3720. THEN IN SERVICE QTY HYD 3 WENT TO O PSI. LEAK APPEARS TO BE FROM THE NR 3 HYD PRESSURE LINE FROM PYLON UNDER 617AB. REMOVED AND INSPECTED RT ENGINE CASE DRAIN FILTERS. NO DEBRIS NOTED. INSTALLED NEW FILTERS. NEEDS LEAK CHECK. IAW AMM 29-12-30-2-1. CHECKED THE NR 3 ENGINE CASE DRAIN FILTERS IAW AMM 29-12-42-6, AND LEAKED CHECKED IAW 29-00-00-6. NO LEAKS NOTED. OK FOR SERVICE.