Thank you for your reply. When I took out the jet pump I removed it completely from the tank together with 3 hoses it comes with. I cleaned everything there was. Also took my vacuum cleaner and put all 3 hoses in it and created a sealed connection so that if there would be any debris in them it would come out. I can't even think of anything that could go bad on that jet pump. There are no moving parts or anything. Except for some ball bearing and small spring at the bottom of the pump which I also cleaned and put back together. How would it go bad ?