What was found
WITH APU RUNNING EXHAUST FUMES ENTERING AIRCRAFT.DURING TRANSIT CHECK FOUND BIG FUEL LEAK FROM FCU APU , CHECKED WITH ALL MAIM FUEL PUMPS ON ,APU OFF NO MORE LEAKS NOTED ,FOR THAT REQUEST DISPATCH A/C IAW MEL 4911F MEL 4911F PLEASE APPLY 4911D AS PREVIOUSLY AGREED. DURING TRANSIT CHECK FOUND BIG FUEL LEAK FROM FUEL CONT UNIT APU ,CHECKED WITH ALL MAIN PUMPS ON AND APU OFF ,NO MORE LEAKS NOTED, T/S OPERATED APU. FOUND FUEL LEAKING FROM FUEL CONTROL UNIT. REMOVED AND REPLACED APU FCU PER AMM 49-31-01. DURING INSTALLATION CHECK, APU HAD AUTOSHUTDOWN FOR MAINT MSG 49-31171 (FUEL FLOW DISAGREE WITH COMMAND). PER FIM 49-11 FT 871, REMOVED AND REPLACED FUEL FLOW DIVDER PER AMM 49-31-12. FCU AND FLOW DIVIDER OPS AND LEAK CHECK IS GOOD AT THIS TIME. APU OPERATES NORMALLY. MEL PLACARD REMOVED.C/W IDT REQUIREMENTS FOR FUEL CONTROL UNIT IRW AMM 49-31-01-404-006-001