What was found
STRONG EXHAUST FUEL, OIL ODOR STARTING THRU 18,000 FT AND INCREASING INTENSITY THROUGH CRUISE AND DECENT. UNABLE TO ISOLATE ISSUE AND USED OXYGENMASK FOR THE DURATION OF FLIGHT. INSTALLED NEW COALESCER SOCK. OPS AND LEAK CHECKED GOOD. WORK DONE IAW MM 21-50-00. RAN AIRCRAFT APU SLIGHT ODOR OF OIL STILL PRESENT, SHUT DOWN THE APU WAITED 10 MINUETS AND CHECKED OIL LEVEL FOUND APU OIL OVERSERVICED, REMOVED 4OZ OF OIL TO OBTAIN PROPER LEVEL IAW MM 49-10-00. REPEATED PROCEDURE IN TC-680-21-120905M REASSEMBLED SEPARATOR AND REINSTALLED IN AIRCRAFT IAW MM 21-50-00, OPS CHECKED WITH ODOR NO LONGER PRESENT.