TC reported TIMS showed rear DT car airdryer fault. ~~~~~ 3674 TC reported TIMS showed air dryer fault.  3674 found FC 704 (air dryer fault). Replaced #3674 air dryer. Function check air dryer operation - OK.  Alan/Lee PT 44531 #3674 Air Dryer S/N :    OLD : 3515480322 NEW : 3517470123