Hotbox/hot wheel triggered on car 3679 ( ~~~~~ 3679 Hotbox/hot wheel triggered on (A1,89)  3679 Check gearbox and axle box temp stickers - ok. No signs of overheating, no oil nor grease leaking. Brake shoes and brake function - ok. Found A1 & B1 wheels having thermal cracks all round. Brakes able to release physically, no residual pressure at COAST. Preventively replaced temp stickers. Limited movement and depot shunting - ok.  Aliff 45370