What was found
UPON ARRIVING AT THE AIRCRAFT APU WAS RUNNING AND SMELLED LIKE DIRTY SOCKS. TURNED OFF APU BLEED, SMELL IMPROVED. TURNED APU BLEED BACK ON, SMELL INCREASED. INTIAL INVESTIGATION FOUND APU OVER SERVICED. REMOVED EXCESS OIL IAW AMM 49-80. UPON FURTHER INVESTIGATION FOUND OIL LEAKING FROM FUEL PUMP MOUNT. REPLACED SEAL AT FUEL PUMP IAW AMM AMM 49-32. R & R RECIR FAN FILTERS IAW AMM 21 -21. REF MD LOG 1523895 FOR ODI PREVENTION. (LP: 8617266) AIRCRAFT WAS GROUNDED