What was found
MOMENTARY INDICATION OF NR 2 BLEED MANF FAILURE. (RED LIGHT ON OVERHEAD AND RED LINE ON NR 2 BLEED MANF SYNOPTIC). ASC DEPRESSURIZED NR 2 MANF. QRH PROCEDURES ACCOMPLISHED. PHONE PATCH W/MEM GOC ADVISED TO CONTINUE TO NANDI. PERFORMED DECAY CHECK AND DECAY CHECK FAILED PER JRH. OPENED ENGINE PER MM REF 71-10-00-2 AND INSPECTED FOR BLOWN DUCTS AND LEAKS. NO DISCREPANCIES NOTED. PER MFC FAULT OPENED PRECOOLER AREA AND FOUND PRECOOLER LEAKING. REMOVED AND REPLACED PRECOOLER PER MM REF 36-13-01-2-2.OPS AND LEAK CHECK GOOD. PERFORMED DECAY CHECK AGAIN PER JRH AND DECAY PASSED.CLOSED ENG & PATIO PER MM REF 71-10-00-2-1. DUE TO AIR TURN BACK.