What was found
AFTER APU VERIFICATION TO ETP AT TOP OF DESCENT, APU STARTED NORMALLY AND ALL INDICATIONS NORMAL FOR .5 SECONDS THEN APU SHUT DOWN WITH ASSOCIATED "APU FAULT" ON EICAS. BIT OF ECU SHOWS LOW OIL PRESS. APU SHOWS SIGNS OF EXTERNAL LEAK, APU OIL QUANTITY INDICATION OUT OF SIGHT GAUGE. FILLED OIL TO FULL, CLEANED APU OFF, CHECKED EXHAUST AND T/S PER FIM 49-11-00. NO DISCREPANCIES NOTED. RAN APU UNDER LOAD FOR OVER 1HOUR. NO LEAKS NOTED APU QTY STAYED AT FULL.