Passenger feedback hissing sound. Staff3631(ORC) checked and feedback hissing sound at Rear DT car 'B2'door. Video sent to IMCC (RS). TC after changing end, feedb ack hissing sound at car 3632 'B2' door. Train scheduled for ~~~~~ Passenger feedback hissing sound. Staff   Found #3632 MR Safety valve keep blowing, checked #3632 air compressor cut in/out ok within criteria. Further check #3631 air compressor cut in 8.6 bar, cut out 10.9 bar, causing safety valve to purge. Preventively replaced #3632 safety valve. OPS 20 to replace #3631 CG. Done by: Pravin, Sudin, Gopal (28.6.24) To C/O 3631 CG   CG c/o done. Cut in 8.6 bar. Cut out 10.4 bar. Charging time: 2 min 5 sec Air leak test: 0.4 bar/ 5 min Done by: Sanip, Koh, Jack (28.6.24)