1701 BRAKE SELF TEST FAILED DUE TO BCU F ~~~~~ 1701 - BRAKE SELF TEST FAILED DUE TO BCU FAULT.  1701 EP 2002 showed #1701 Bogie 2 rio valve brake cylinder slight leak. Found #1701 A3 TBU/Parking Brake Unit internal leak causing service brake intermittently unable to hold.    Isolated all TBU on #1701 Bogie 2 by disconnecting service brake hose & blanking. Notification 2559816 raised for TBU changeout.  Celine 45302 Notif 2559816 Name(Requestor)ßßßßßßßßßßßßß : Celine Date of occurrenceßßßßßßßßßß : 11/01/2024 Last service dateßßßßßßßßßßß :   EMU/Equipment/Locationßßßßßß : 1701/A3 TBU With Parking Brake                                   Unit Equipment Serial No.(if any) :   Description of fault/Causeßß : Internally Air Leak Causing Brake                                Self Test Fail Measurement (if any)ßßßßßßßß :   Fault found during CM or PMß : CM Required rectificationßßßßßß : To Replace A3 Brake Unit