As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING LANDING ROLLOUT TOWER ALERTED CREW OF SMOKE/VAPOR IN WHEEL WELL AREA. BAA REQUESTED MTC CHECK PRIOR TO TOW ONTO STAND. AFTER INSPECTION, FOUND NR 4 BRAKE UNIT LEAKING AT BRAKE CYLINDER. ISOLATED SYSTEM AND TOWED ONTO STAND. BRAKE REPLACED PER MM AND ALL CHECKS OK.