do a couple of boil washes 90* deg no clothes in and bleach added but i think the mould and gunge will have eaten into the rubber pipes by now ,build up is caused by a lot of LOW TEMPERATURE washes 40 degree or less being done in machine. Most washing machine makers in ENGLAND now recommend a service wash (90*) degrees monthly to kill the mould/gunge in the pipes.
wirecutterman, February 2008