3554 DT check found bogie 2 having heavy ~~~~~ #3554 Check and found B4 parking brake heavy air leak.Tread brake unit need to c/o.Send notification to RSW done. Additional finding #2554 ACU exhaust port air leak.Replaced ACU and function check ok. Not: 2133050-Tread brake unit c/o. ACU-Old s/n: 1019-017  New s/n:1019-018 Not: 2132960 raise to RSW. Done by Jack/Sateesh/Koh. 20/02/20