As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
GROUND STAFF REPORTED SMOKE FROM NO4 BRAKE WHEN ARRIVING ON RAMP AFTER LANDING AT KAGS. BRAKE TEMP INDICATION WAS WELL BELOW WARNING FOR HOT BRAKES, INDICATED <250C. UPON INSPECTION FOUND ONE OF THE PISTONS HAVING BROKEN A SEAL AND LEAKED FLUID ONTO THE WARM BRAKE, REASON FOR SMOKE. AIRCRAFT GROUNDED AND BRAKE REPLACED.