What was found
(CAN) IN CRUISE FLIGHT THE NR 2 HYD PUMP CAUTION LIGHT ILLUMINATED FOLLOWED BY THE NR 2 HYD ISO VALVE C/L, THE RT HYD QTY WAS OBSERVED TO BE DEPLETED. AFTER AN ALTERNATE GEAR EXTENSION THE ACFT HAD AN UNEVENTFUL LANDING. MAINTENANCE INVESTIGATION FOUND THE RT HYDRAULIC PUMP WITH HOLES IN THE BODY WHICH APPEAR TO BE CAUSED BY INTERNAL BREAKUP OF THE PUMP. THE CASE DRAIN AND PRESSURE FILTERS WERE HEAVILY CONTAMINATED WITH METAL AND WERE IN BY-PASS. DUE TO METAL CONTAMINATION THE PTU AND ALL SYSTEM FILTERS WERE REPLACED AND THE HYDRAULIC SYS WAS FLUSHED. THE EDP WAS REPLACED.