What was found
FLIGHT ATTENDANT SMELLED A DIRTY SOCK ODOR AFTER APU BLEED AIR TURNED ON. THE ODOR WAS DETECTED RIGHT AFTER TAKEOFF AND 1:36 HOURS INTO FLIGHT, DESCENDING +20 UGH 200 HP. BLEED VALVE OPEN, DIRTY SOCKS ODOR REPEATED 230-190. CONTINUED DURING FINAL APPROACH PHASE. PERFORMED INFO NOTICE 2017-T015B, AND ISOLATED THE ODOR TO APU. PERFORMED TSM 49-00-81-810-874-A. FOUND AN OIL LEAK FROM THE OIL COOLING FAN AND CONTAMINATION OF COOLING FAN DISCHARGE DUCTING. REMOVED AND REPLACED THE COOLING FAN ASSY IAW AMM 49-52-51, AND CLEANED DUCTING, OPS & LEAK CHECKED OK. R & R THE NR 1 & 2 PACK CONDENSERS IAW AMM 21-52-32. OPS NORMAL. R & R NR 1 & 2 PACK OZONE FILTERS IAW AMM 21-51-41. OPS NORMAL.