What was found
DURING FLIGHT 3489, GREEN SYSTEM HI TEMP LIGHT ILLUMINATED. GREEN HI TEMP CAME ON AT CRUISE PER QRH TURNED OFF THE PUMP HI TEMP LIGHT TURNED OFF AFTER 3 TO 4 MINUTES. AIR RETURN TO MSP. MAINTENANCE REMOVED & REPLACED NR 3 EDP P/N 521449, S/N OFF F9840491, S/N ON F9727550 IAW AMM 29-10-17, OPS AND LEAK CHECKS GOOD REF 409 194685 FOR DETAILS.