Train stopped with intermittent stuck brake indication at car 1649 after arriving RFP NB. Fault clea red by itself. ~~~~~ Train stopped with intermittent stuck br     #1649 Fault code 330,331,308,314,312,downloaded ER on PTU 006.Brake cyclic test found #1649 ACU air leak from exhaust port when put to coast.Replaced ACU mod4 and brake cyclic check ok.BCP checked within range.No stuck brake found. 31649-ACU: New s/n: 1503-070(mod4)  Old s/n: 1528-131 Not: 2167365 raise to RSW. Done by Saini/Yusof/Haffiz/Syfiq/Najmuddeen. 06/06/20