What was found
CREW REPORTS SMOKE/HAZE IN CABIN ON TAXI-OUT, ALSO RECEIVED APU OIL PRESS AND APU OIL TEMP CAUTION MESSAGES, ACCOMPANIED BY APU SHUT DOWN. OIL FOUND ON BELLY AND IN ENCLOSURE UPON GATE RETURN. ***AIRCRAFT REMOVED FROM SERVICE*** MX IN PROGRESS *****SUPPLEMENTAL INFORMATION****** CREW REPORTS SMOKE/HAZE IN CABIN ON TAXI-OUT, ALSO RECEIVED APU OIL PRESS AND APU OIL TEMP CAUTION MESSAGES, ACCOMPANIED BY APU SHUT DOWN. OIL FOUND ON BELLY AND IN ENCLOSURE UPON GATE RETURN. ***AIRCRAFT REMOVED FROM SERVICE*** FOUND APU OIL COOLER LEAKING. REMOVED OIL COOLER IAW AMM 49-91-07. REF 334869-4 FOR INSTALLATION. INSTALLED OIL COOLER IAW AMM 49-91-07-400-801 OPS AND LEAK CHECK GOOD