TC reported that TIMS show train doors at Rear DT car were slow in closing. Staff(OTP) checked and c onfirmed Rear DT car 'B1' doors were slow in closing. Fault recurred at subsequent stations. Staff(OTP) assisted to isol ~~~~~ #3624 B1 door found roller damaged.replaced new roller done.function check ok.20mm ok.door cylic test ok.door open/close time ok.closing distance ok Victor 21.07.2023