Problem next to pool pump? I have a impressively old 20x40 inground pool next to one...

I have a impressively old 20x40 inground pool next to one skimmer and one jet. My spray is blowing a lot of nouns and pressure is low and drops to nothing later goes rear to low. Can someone give me a step-by-step on what to check first to ending? I have checked the skimmer picnic basket and pump basket for driftwood and there are no noticeable water leak above ground. Will the pump basket dribble if the seal is impossible? If all else is right and it is a problem with the smudge from skimmer to pump, how do you find or fix that? I also just replaced the top of the sand filter, could that own anything to do with it?
Thanks contained by advance!
What is a "Floor beam" and a "joist"?
Answers:    here is a page near a few tips: http://www.swimming-pool-information.com... a shaft seal can contribute to the problem
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