I have had the same problem, and found that the part is not available.
It is not the tube, but when you plug the tube into the machine the bit the steam pipe connects too has broken, and it pushes back. The way I fixed it was to Take the machine apart, Glue, with araldite, the plug onto the fixing plate, making sure that glue does not interfere the connector. Andy
                
 Andy Taylor
                
 September 2007