What was found
(CAN) AFTER PUSHBACK, STATION ADVISED THE CREW THAT LIQUID WAS DISCOVERED ON THE GROUND AT THE GATE IN THE VICINITY OF WHERE THE MAIN GEAR WAS POSITIONED. CREW ELECTED TO RETURN TO THE GATE AND NOTED A DECREASE IN THE RT HYD QTY. ATC WAS NOTIFIED AND EMERGENCY EQUIPMENT REQUESTED. AT THE GATE SMOKE WAS EMANATING FROM THE LT BOGIE AND THE CREW ELECTED TO DEPLANE THE PASSENGERS. NR 1 BRAKE FLEX HOSE REPLACED IAW AMM 32-41-16-401 C/OUT. NR 1 BRAKE SERVICEABLE.