What was found
MNL - FLT 876 - DURING CRUISE GOT A BLEED TRIP ON NR 3 ENGINE, SELECTED NR 2 BLEED SOURCE. TRIED TO RESET NR 3 DUCT PRESSURE, STILL PLUS 100 PSI. AFTER SELECTING NR 2 BLEED GOT AFT BODY OVERHEAT LIGHT. AIR RETURN. REMOVED AND REPLACED 13TH STAGE MOD VALVE FOR NR 3 BLEED TRIP, OPS CHECK NORMAL. FOUND LEFT PURGE VALVE CLAMP LEAKING ONTO AFT BODY O/H SENSOR. REPOSITIONED AND SECURED CLAMP LEAK CHECK GOOD. (M)