What was found
AIRCRAFT WAS GROUNDED: CREW REPORTED THAT DURING THE BOARDING PROCESS WITH THE APU BLEED AIR ON, THE PACKS WERE EMITTING A BAD ODOR CAUSING EYE IRRITATION. MAINTENANCE FOUND THE APU SCAVENGE FILTER LEAKING OIL AND REPLACED THE O-RING IAW AMM 49-91-41. THE SURROUNDING AREA WAS CLEANED AND A SATISFACTORY LEAK CHECK WAS ACCOMPLISHED. DECONTAMINATION TC 26L00021004 WAS ACCOMPLISHED WITH NO ADDITIONAL ODORS BEING NOTED.