I fixed a rat eaten pipe had to do the usual stuff to get rid of airlocks,3bathrooms,2off this problem immersion/pump.I have used a wet vac got water out of pipes,I have opened up joints got air out of these also,but still after a minute of pumping water trickles off stops!I have done a lot of plumbing as I say,I have tried a lot of Tricks.now I'm Stumped!thanks to anyone for tips,Paul

I bled the flow pipe into the immersion and it blew out the airlock