3538-AIR LEAK FROM CONTROL VALVE COMPART ~~~~~ 3538 REPORTED DURING TRAIN PREP MR PRESSURE U BLE TO BUILD UP.  3538 LOCAL ON & found air dryer leaking When air compressor was running, MR was unable to charge up. Checked #3538 air dryer terminal box connection, no abnormalities. Replaced #3538 air dryer. Security/function check - OK. Performed pneumatic system check - OK. (refer to attachment)  Isam/Faiz/Fudail/Izzul 44922 #3538 Air Dryer S/N : OLD : 3517280349 NEW : 015-13240