Diafragma

It really is worth replacing this item whenever you service or overhaul your braking system, it does not cost much, and even a barely visible pin prick may allow air bubbles to form and give the impression of spongy brakes!

For your entire braking area consumables, check out the online catalogue or 'parts list' fiche for your model, this may help you specify ALL the parts you require for a satisfactory out come when overhauling your brakes.