What was found
ON FLIGHT 2154 EUG TO SEA AICRAFT DIVERTED TO PDX DUE TO NR 2 HYDRAULIC PUMP CAUTION ILLUMINATED AFTER TAKEOFF AND REMAINED ILLUMINATED UNTIL LANDING IN PDX. GEAR AND ASSOCIATED DOORS REMAINED EXTENDED FOR FLIGHT. ASSOCIATED NR 2 HYDRAULIC QUANTITY AND PRESSURE WENT IMMEDIATLY TO ZERO AFTER GEAR HANDLE WAS RETRACTED. ENGINE OPERATED WITH ZERO PRESSURE AND QUANTITY FOR APPROXIMATELY 55 MINUTES. AIRCRAFT LANDED SAFELY. REMOVED AND REPLACED ENGINE DRIVEN HYDRAULIC PUMP. OPERATIONAL CHECKS GOOD. AIRCRAFT RETURNED TO SERVICE.