What was found
B RSVR LO LEVEL DISPLAYED ON UPPER ECAM SCREEN. HYD APPLIED ECAM PROCEDURE LEAK APPEARS FROM BLUE SLAT PCU VALVE BLOC FILTER, IPC 27-84-53-01A PACKING ITEM 60 PART NR NAS1612-BA FOUND BLUE SYSTEM LOW, CAUSE VALVE BLOCK FILTER ORING OF BLUE. REPLACED ORING, PER AMM 27-84-53-400-003-A. SLAT SYSTEM CHECK NORMAL, FILTER CLEAN. RAN SPOILERS, CYCLED ALL OTHER FLIGHT CONTROLS. HYD SYSTEM SERVICED TO NORMAL, NO LEAKS. OK RETURN TO SERVICE.