TC feedback train had a slow pickup in Auto mode for a distance of 10 metres departing station. Trai n was able to proceed as per normal afterwards. No other fau lt indications. ~~~~~ 3673-TC feedback train had a slow pickup in AM for a distance of 10 metres departing station. Train was able to proceed as per normal afterwards. No other fault indications.  2673 replaced ACU. Brake cyclic test & pressure check after ACU replacement - OK. At COAST, all 8 brake shoes were physically released with clearance from wheel. Checked CCD shoes/fuses/cable/height - OK. Replaced 1x 'OL' CHRe1 resistor. Limited movement/depot shunting, no brake/power fault.  Hanafi/Chan SW 44519 #2673 ACU S/N : OLD : 1538/168 NEW : 1429/04