What was found
(CAN) DURING FLIGHT, CREW NOTICED NR 2 HYD ISO VALVE CAUTION LIGHT CAME ON, NR 2 HYDRAULIC PRESSURE REMAINED NORMAL, AND THERE WAS A "SMALL QUANTITY" OF FLUID REMAINING IN NR 2 SYSTEM. CREW DECLARED EMERGENCY LANDING. CREW PERFORMED AN ALTERNATE GEAR EXTENSION, AND ACFT LANDED. ACFT TOWED TO HANGAR WHERE TECHNICIANS DISCOVERED HYDRAULIC FLUID DRIPPING FROM NR 2 NACELLE, O/B OF JET PIPE CENTER SECTION. JET PIPE REMOVED AND TECHNICIANS DISCOVERED A SPLIT IN THE HYDRAULIC LINE, WHERE IT HAD BEEN CHAFFING ON THE FWD JET PIPE SHROUD DAMAGED LINE WAS PART OF MLG `NR 2 GEAR UP` PIPING, P/N 82974351-003. LINE TO BE REPLACED.