What was found
DURING CRUISE ON FLIGHT 3528, IN DTW, YELLOW SYSTEM HI TEMP LIGHT CAME ON DURING CRUISE. QRH MAINTENANCE REMOVED AND REPLACED ENG DRIVEN PUMP, L/P FILTER, AC PUMP, AND YELLOW SYSTEM TEMP SENSOR. SEE MM 409 CARD NR 133380 FOR DETAILS. ALL CHECKS GOOD AT THIS TIME.