British Airways A320 at Prague on Mar 9th 2014, loose nut

A British Airways Airbus A320-200, registration G-EUUT performing flight BA-858 from London Heathrow,EN (UK) to Prague (Czech Republic), had landed on Prague's runway 24 and was about to taxi to the apron when ground personnel observed smoke from the right hand main gear and notified tower, who dispatched emergency services to assist the aircraft. Emergency services established that the smoke was result of hydraulic fluid dripping onto the hot brakes.

Czech's UZPLN reported in their quarterly bulletin that after cooling the brakes mechanics found a leak at brake #4, where the hoses for the green and yellow hydraulic systems connected to the brake. The nuts on those hydraulic connectors were tightened and the brakes tested without fault.