What was found
RIGHT HYDRAULIC SYSTEM QUANTITY DROPPED TO LESS THAN 3 QUARTS DURING DESCENT. COM PROCEDURES COMPLIED WITH AND PRESSURE WAS NORMAL. FLIGHT LANDED WITHOUT INCIDENT AT IAH AND THEN HYDRAULIC QUANTITY DROPPED TO ZERO AFTER TOUCHDOWN. MAINTENANCE FOUND A LEAK AT THE PRESSURE OUTLET OF THE AUXILIARY HYDRAULIC PUMP. THE ELECTRIC AND THE ENGINE DRIVEN PUMPS ALONG WITH ALL FIVE OF THE RIGHT HYDRAULIC SYSTEMS FILTERS WERE REPLACED. THE AIRCRAFT HAS RETURNED TO SERVICE.