After 8 years of normal operation I have suddenly started see lots of bubbles coming out of my return lines into the pool. I have tightened all of the fittings and think they are tight. The pump (a Hayward 1.5 hp Super pump) has also gotten noisier, I suspect I might have a problem with the pump seal. How commonis this , how easy is it to repair, is it better to jsut replace the pump