3657 DC reported BCU fault. ~~~~~ 3657 DC reported BCU fault.  2657 found having intermittent stuck brake. Found 2657 ACU having continous air leak at exhaust port. Replaced 2657 ACU. Function test & no indication stuck brake found. Checked all brakes - OK. 2657 ACU S/N : OLD : 1523/114 NEW : 1511/089  Selvan/Anand 43847