What was found
FLT 3640, EN ROUTE TO BWI, THE NR 2 HYDRAULIC SYSTEM INDICATED ZERO QUANTITY. AIRCRAFT LANDED WITHOUT INCIDENT. MAINTENANCE INSPECTED SYSTEM, FOUND THE HYDRAULIC LINE AT THE NR 2 GEAR ACTUATOR AT FAULT. INSTALLED A FLEXIBLE LINE PER MANUAL PROCEDURES. CHECKED SYSTEM PER CHAPTER 05. SUBSEQUENTLY, THE HYDRAULIC FLEXIBLE LINE WAS REPLACED WITH ORIGINAL EQUIPMENT. AIRCRAFT RETURNED TO SERVICE.