What was found
AFTER FLAP RETRACTION GOT SMOKE IN THE COCKPIT, WENT ON OXYGEN, DECLARED EMERGENCY AND RETURNED TO NRT. SMOKE GRADUALLY DISSIPATED OVER ABOUT 15 MIN. OPENED ALL 3 ENGINES AND CHECKED FOR OIL LEAKS IN PNEUMATIC SYSTEM, NO LEAKS FOUND. REMOVED AND REPLACED ALL 3 A/COND WATER SEPARATOR BAGS MM:21-54-01. ALSO CHECKED APU BLEED SYSTEM FOR OIL LEAKS AND NONE FOUND. REMOVED ALL 6 DU`S, NO EVIDENCE FOR OVERHEATING. ALSO CHECKED AVIONICS COMPT FOR POSSIBLE SHORTS AND NONE FOUND. THEN RAN ALL 3 ENGINES WITH ALL BLEEDS ON AND NO ODOR FOUND.