What was found
(CAN) THE FLIGHT CREW REPORTED LOSS OF YELLOW SYSTEM HYDRAULIC FLUID APPROX. 15 MILES BACK ON DESCENT. AN ODOR WAS EXPERIENCED BY PAX IN ROWS 7, 8 & 9 FIRST. A NORMAL LANDING WAS ACCOMPLISHED. MAINTENANCE INVESTIGATION REVEALED A LEAK AT THE B PORT OF THE YELLOW SYSTEM PRESSURE MANIFOLD. THE MS ADAPTER FITTING HAD FAILED IN THE THREAD AREA AND CAUSED SYSTEM FLUID LOSS. THE FITTING WAS REPLACED AND THE AIRCRAFT WAS RETURNED TO SERVICE.