TIMS showed BCU fault at front m1 & rearm1. Train proceed in ATPM to next station, Fault self clear ed and departed KTB2 in Auto. ~~~~~ TIMS showed BCU fault at front m1 & rear     Found #1523 was abnormal air puring from exhaust port and observed in Tims show slow release at B1 to coast.BCP intermitted stuck at 0.35bar and found PBSV internal air leak. Replaced PBSV and tested ok.ACU change out and brake function test ok. ACU-Old s/n: 1042-075  New s/n: 1912-157 Not: 2261737 raise. PBSV-Not: 2261741 raise. Done by Zul/Faddzal/Sateesh/Kalees. 29/03/21