Train doors at rear DT car not proven closed. TC opened and closed train doors few times - no avail.Pax were disembarked. DIRBS was operated for train to withd raw back to depot. ~~~~~ Fault could be duplicated in depot Multiple FC for 3618 B4 door close operation timeout. ER reflected as reported 3618 B4 doors had high resistance. Push-pull gauge recorded 14.5 kg. Door leafs unable to roll smoothly. Removed door leaves and checked door rollers - found 3618 B4 LHS and RHS roller delaminated. Weather strip not inhibiting door movement. No rubbing marks observed. No FOD found along guide rail. No signs of FOD being dislodged. Cleaned J-rail and guide rail. Replaced 3618 B4 LHS and RHS door rollers. Checked door resistance satis, able to roll smoothly. Performed door cyclic test satis. DIR and DMI able to light/extinguish. Performed door static test satis. Normalised DIRBS LAI.M.K/AZLI/FAIZAL/14.02.23