TC reported train doors at car 2631 didnot opened. Staff(BBT) checked and confirmed car 2631 'B4' d oor did not opened. Staff(JUR) reported door delayed in open ing and manage to close in auto. TC reported train doors at ~~~~~ TC reported train doors at car 2631 did not opened. Staff(BBT) checked and confirmed car 2631 'B4' door did not opened. Staff(JUR) reported door delayed in opening and manage to close in auto.  No FC. Checked and found #2631 B4 LHS outer door roller damaged. Changed out both LHS and RHS door rollers to iron rollers. Mating strip, DLS red line, DLS lock nut secure, top rubber present. Push pull test ok. Door cycle and door static test ok. Done by: Jack/Sanip/Rizman/Koh 45298