Washing machine (Raveningham NR14)

Top loader, Direct Drive 8kg load.
Needs hot and cold water feed.
It is in good working order but each wash now produces small deposits of brown flaky stuff on the laundry. It washes off so not staining just annoying! I have tried cleaning the filters, the washing machine itself several times, but although getting less it is still over the inside of the drum. If you can solve the problem you'll have a very good washing machine!