What was found
FLIGHT ATTENDENTS REPORTED DIRTY SOCK SMELL AT GEAR DOWN THRU ENGINE SHUTDOWN, ODOR CAME AND WENT IN THE FRONT, BACK FA'S REPORTED SIMILAR ODOR AT 8000 AGL. FOUND APU OIL OVERSERVICED. DRAINED OIL IAW AMM 49-90. INSPECTED APU BLEED DUCT, NO OIL WETTING NOTED IAW AMM 49-51. AFTER APU RUN, FOUND APU OIL LEVEL LOW. INSPECTED BOTH ENG INLET CONES, NO WETTING NOTED. IAW AMM72-15. DURING WC 4900-2001 NO OIL FOUND IN APU BLEED DUCT. FOUND OIL AT APU LOAD COMPRESSOR DRAIN LINE, REPLACED APU. (LP 9583621, 1742877 AIRCRAFT WAS GROUNDED)