What was found
SMOKE IN CABIN AFTER TAKEOFF. AFT LAV SMOKE DETECTOR ACTIVATED. CKD W/W'S FOR LEAKS, CKD HYD SVC BOTTLES, REPLACED AFT SMOKE DETECTORS, REPLACED WATER SEPARATOR BAGS. FOUND LT WATER SEPARATOR INLET OILY. REPLACED LT ACM, CLEANED APU INLET ASSY AND PLENUM. PERFORMED DUCT BURNOUT. RAN PACKS OFF APU PNEUMATICS AND PERFORMED HIGH POWER RUN. AFTER ENG RUN AND BURNOUT, REPLACED WATER SEPARATOR BAGS AGAIN, PRECAUTIONARY.