What was found
THE RT HYDRAULIC SYSTEM QUANTITY BEGAN TO DECREASE DURING CLIMB. THE R/H HYDRAULIC QUANTITY CONTINUED TO DROP SLOWLY WHILE AT CRUISE. THE TRANSFER PUMP, RT HYDRAULIC PUMP AND AUX PUMP WERE TURNED OFF. THE PUMPS WERE RETURNED TO NORMAL ON APPROACH WITH THE RT HYDRAULIC QUANTITY AT 2 GALLONS. THE AIRCRAFT LANDED WITHOUT INCIDENT. MAINTENANCE FOUND A PINHOLE LEAK IN RT HYDRAULIC SYSTEM PRESSURE LINE LOCATED IN TAIL COMPARTMENT. THE HYDRAULIC LINE WAS REMOVED AND REPLACED. THE RT HYDRAULIC SYSTEM WAS SERVICED TO FULL AND LEAK CHECKS WERE GOOD.