As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LEFT OTBD BRAKE SHOWED OVERHEAT ON TAKEOFF "BRAKE OVERHEAT WARNING" FOLLOWED QRH AND RETURNED TO DEPARTURE. ACFT RETURNED TO DEPARTURE, EMERGENCY DECLARED. CLEANED LEFT OTBD BRAKE TEMP MONITORING SYSTEM ELECTRICAL CONNECTOR AND REATTACHED IAW AMM 3246-01. OPS CHECKED GOOD.