My pump is original from 2002 and is mounted on the floor and the tank is under the floor, so it has to pull UP from the tank..
It holds pressure for DAYS too.. Meaning, I can pressure up the system with the pump.. Come in several days later and flip the switch and it does not trigger to run.. Still has full pressure..
Just saying this to say that just cause a pump has not been 'used' much, but is around 10 years old, can mean all kinds of things can be wrong with it..
Sure, you can chase around the problem, and if you have the time and patience to do that, great...
But, I'd just be buying a new one and move on to the next item on the list of things to do... ;)
Good luck!
Mitch