i had an airlock, wcw said it was not possible.
all i did was take off black base
undo black pipe from from yellow body feed pipe.
switch pump on off few times
then reconnected was fine after that.
now got prob with charger, 6-8 week wait
lee
ps when fixed my freedom trolley will replace pump feed pipe with longer microbore hose, so dosen't have kink in it that black pipe does.