What was found
UPON GEAR EXTENSION FOR LANDING, THE RT HYDRAULIC SYS FLUID QUANTITY WENT TO ZERO. LANDING GEAR LOCKED DOWN AND SAFE WITH NO FURTHER PROBLEMS. AUXILIARY HYD PUMP WAS SHUT OFF AFTER LANDING. NO MENTION OF COM COMPLIANCE OR OF OTHER HYDRAULIC SYSTEM INDICATIONS LIKE PRESSURE OR TEMPERATURE. MAINTENANCE FOUND A FAILED FLEX LINE AT THE AUXILIARY PUMP AND A LEAKING RUDDER POWER SHUTOFF VALVE. REPLACED BOTH AND THE AUXILIARY PUMP AND ASSOCIATED FILTERS. AIRCRAFT RETURNED TO SERVICE.