What was found
STARTING AT 7000 FT, STRONG ODOR FROM PACK, SMELLS LIKE WET SOCKS. PILOT REPORT A FUME LIKE PACK OIL SMELL ONLY ON DECENT BELOW 10,000 FT SO STRONG,PILOT FELT LIKE PASSING OUT. SMELL ONLY IN COCKPIT & ONLY ON DECENT, FWD CARGO PIT AFT WALL LT SIDE REMOVED FOM. OLD RECIRC FILTER STILL INSTALLED, TSM 05-50-00-810-831 TO START TROUBLESHOOTING. REMOVED RECIRC FILTER TO EVALUATE CONDITION, FOUND DIRTY. RECIRCULATION FILTER IS MM 21-21-45. WITH APU RUNNING SELECTED PACK TEMP TO HOT & COLD WHICH DID NOT PRODUCE ODOR. REPLACED OZONE & PACK FILTERS IAW AMM 21-00-00-615-802-A. ACCOMPLISHED AMM 49-00-00-200-811-A UP TO BUT NOT INCLUDING STEP 4. F., NO DEFECTS OR FINDINGS TO REPORT. COMPLETED INSPECTION OF APU FROM STEP F.1 TO END REF MM 49-00-00-200-811-A, NO SIGNS OF OIL OR FUEL LEAKS.