I’m having an issue again with the Kamoer FX-STP pump on which Coralvue replaced the motor last July. The pump is working but making a loud clicking noise again. This is what happened last time shortly before the motor failed. I've lubricated the rollers on the wheel and made sure the set screw is tight but the clicking continues. The clicking stops when the tube is removed from the wheel and I run the motor without it in place. Please advise on what I need to do to prevent the pump from failing again.