Train Prep found 3637 BCU fault ~~~~~ Train Prep found 3637 BCU fault  #3637 brakes unable to be released. FC 312 BCU release fault; FC308, 330 and 331. Swapped ACU from #3637 to #3638; fault transferred. Changed out #3638 ACU and tested brakes able to release. Brakes function check ok, brake pressure within criteria. Brake shoes condition ok. Wheel condition ok. Old SN: 1528/063 New SN: 1403/003 Notif: 2606634. DOne by: Koh/Sanip 9.6.24