What was found
AIRCRAFT WAS NOT GROUNDED: AIRCRAFT HAS DIRTY SOCK SMELL DURING ALL PHASES FLIGHT. SMELL DOESN'T GO AWAY WITH APU OFF. MAINTENANCE FOUND A TRAIL OF HYDRAULIC FLUID GOING FROM THE LEFT HAND WHEEL WELL TO THE APU AIR INTAKE AND FOUND THE BLUE HYDRAULIC SYSTEM ELECTRIC PUMP LEAKING FROM THE SPLIT LINE OF THE PUMP BODY. THE PUMP WAS REPLACED AND A SATISFACTORY LEAK / OPERATIONAL CHECK WAS ACCOMPLISHED PER AMM 29-12-51. MAINTENANCE ACCOMPLISHED DECONTAMINATION OF THE PACK SYSTEM PER TASK CARD 26L00021013.