What was found
AIRCRAFT WAS GROUNDED: CLIMBING THROUGH 17,000 AFT FLIGHT ATTENDANTS CALLED AND SAID THERE WAS A BAD ODOR IN THE AFT GALLEY. THEY SAID ODOR STARTED JUST AFTER TAKEOFF. NOTHING ELSE WAS SAID UNTIL ABOUT AN HOUR INTO THE FLIGHT. AT THAT TIME THE ODOR HAD DISAPPEARED. ONE FIGHT ATTENDANT WAS NAUSEOUS AND OTHER FELT FAINT. COMMUTING FIRST OFFICER CHECKED FOR US AND SAID IT SMELLED LIKE OLD AIRPLANE. REMOVED AND REPLACED AFT SILL DRAIN FLOAT VALVE FOUND CLOGGED PER AMM 38-31-06.