If they are not too corroded you can just do seal kits. If the end caps are really bad you can replace them also. Unless you can't get the end caps out the cylinders should be OK. It it is a salt water boat it can be tricky to work on the stuff.

I once had a clogged filter screen on the pump inlet tube in the fluid reservoir. Not sure how it got clogged but everything worked fine after cleaning.

When you say you hear it running, is it clicking or no it sounds like it normally does when operating correctly? "Typically" with these pumps the problem is usually dirty connections or bad solenoids both at the pump itself. Depending upon how easy they are to get to, you can jump the solenoids to see if they're maybe bad. Assunming all else is on par like proper fluid levels ad clean connections.

If you search online you can find some troubleshooting steps to eliminate the simple stuff.

Reckless, I can hear the motor run, in fact the first thing we noticed was the indicators not moving, it sounded like they were working fine.