As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
NR 2 LT ZONE HI TEMP LIGHT ILLUMINATED EN ROUTE. AIR TURNBACK TO DTW. UPON INSPECTION MAINTENANCE FOUND PERI-SEALS LEAKING AT LEADING EDGE ON NR 1 PYLON, REMOVED AND REPLACED PERI-SEALS IAW AVRO MM CHAP 30. P/N 460-200. PERFORMED GROUND RUNS AND ANTI-ICE SYSTEM AND LEAK CHECK GOOD, ALL CHECK GOOD AT THIS TIME.