wow, what has happened here?
it seems that the pump/tube has been very long in use and/or the fluid is too viscous or has too many/ too big solid parts in it, friction become too high which resulted in damaging the tube from the inside and moving the whole tube from the left to the right
-> complete pump must be replaced
-> you should not pump the fluid - whatever it exactly is - with the new pump
better you let check the entire doser before a serious malfunction happens, caused by penetrating fluid
contact us or your distributor