What was found
HEAVY MUSTY ODOR IN CABIN & COCKPIT PRESENT. ACCESSED BOTH COALESCER SOCKS & NOTED OIL RESIDUE. INSPECTED APU BLEED VALVE, ENG 1 & 2 AIR DUCTS NO OIL NOTED. PERFORMED A GENERAL INSPECTION OF THE APU INLET, AIR DUCT & COMPARTMENT, SIGNS OF OIL NOTED. COALESCER SOCKS REMOVED. APU CB'S PULLED & FLAGGED. REMOVED APU IAW MM 49-10-00. CLEANED SOCKS & INSTALLED FOR DUCT BURN. SWAPPED DC GEN, SWAPPED FIRE DETECTION LOOP, SWAPPED INLET DUCT. INSTALLED APU & DUCTING, CONNECTED & TORQUED ACFT FITTINGS & ELEC CONNECTIONS, SERVICED APU WITH OIL. PERFORMED OPERATIONS CHECK & LEAK CHECK OF APU, OPERATIONS CHECK LEAK CHECKED GOOD IAW AMM 49-10-00, 24-32-00 & 20-10-35 FOR WORK PERFORMED. R & R LT & RT COALESCER CLOTHS & O-RINGS WITH NEW IAW MM 12-10-01. OPS & LEAK CHECKED GOOD.