RSM(AMK) and ASM(TAP) feedback that airdischargesound was heard at rear DT car. Staff(TAP) checke d and confirmed air discharge sound heard at RDT car. TC con firmed MR 10 bar and no compressor fault. Stock change-over ~~~~~ #3551-A/S WFL elbow hose connector faulty.    Replaced elbow hose connector and function test WFL-OK. Done by Asruddin. 27/10/20.