T115 encountered stuck brake at front M2while departing BDK2. STBS operated and train proceeded in ATPM to KEM2 for disembarkment. ~~~~~ L3 2540 no air leak found on faulty ACU. Replaced ACU & function test - OK.    ER D/L & all cars ACU serial No. taken & attached. No air leak found on new ACU & limited movement. No fault reoccurred, STBS on 3540 resealed & BIC on 2540 normalised. No fault recorded on TIMS ER after ACU replacement. Awaiting clearance. 2540 ACU S/N : OLD : 1240/093 NEW : 1019/019 SV S/N :        3539      1539      2539      2540      1540      3540 RF : 1747/453  1733/439  1747/478  1844/326  1747/480  1744/119 RC : 1747/476  1733/438  1747/472  1844/078  1747/466  1747/498 AF : 1814/818  1909/613  1814/910  1847/960  1814/608  1814/854 AC : 1814/709  1909/799  1814/819  1847/635  1814/853  1814/605 EM : 1751/697  1739/613  1751/516  1905/937  1851/755  1751/755  Sarma. 02/02/2020. L3 539/540 ACU replaced on 3539, 1539, 2539, 1540 & 3540. Function test & brake pressure test - OK. No residue pressure on all cars @ COAST. No air leak found. Limited movement - OK. ACU S/N :   OLD           NEW 3539      1044/031      1241/044 1539      1002/001      1037/046 2539      1042/068      1038/061 3540      1044/027      1249/045 1540      1042/066      1047/073  Sarma/Kiran. 03/02/2020. L3 539/540 during M/L test, found 2539 brake fault occurred twice from UPD to JKN & vice versa. ER D/L & found FC 331/330/308 was found on 2539 & 3540.  Sarma/Rasul. 05/02/2020. L3 539/540 found EM pressure low on 2539. Swapped ACU on 2539 to another car & confirmed 2539 ACU faulty. Replaced with new ACU. Performed brake pressure cyclic test & B1/B2/B3/EM pressure-OK. 2539 ACU S/N : OLD : 1038/061. NEW : 1240/099.  Selvan/Lee PT/Anand. 05/02/2020. L3 539/540 during shunting, found BCUfault occurred on 3540, 2540 & 2539. Replaced ACU on all the 3 mentioned cars. Brake function test - oK. ACU S/N :    OLD             NEW 3540       1249/045        1048/036 2540       1019/019        1310/141 2539       1240/099        1042/072  Alan/Selvan/Alcus/Anand. 06/02/2020.