What was found
MIA - FLT 692 - AFTER TAKEOFF MIA, DURING CLIMB-OUT, SLIGHT FUMES/ODOR NOTED IN AFT CABIN. AIRCRAFT RETURNED TO MIA AND LANDED WITHOUT INCIDENT. REPLACED ALL COALESCER BAGS AND ACCOMPLISHED GROUND ENGINE RUN AND PACK BURNOUT PROCEDURE WITH NO DEFECTS OR ODOR NOTED. SUBSEQUENTLY, AIRCRAFT DEPARTED MIA AS T1432 EN ROUTE BOS AND PROBLEM INITIALLY REPEATED BUT THEN WENT AWAY. AIRCRAFT PROCEEDED BOS AND LANDED WITHOUT INCIDENT. REPLACED CABIN RECIRCULATION FAN. SYSTEM GROUND CHECKED NORMAL OPERATION. (M)