Ngl, I spent 6 months thinking my dredge pump was losing efficiency because the intake screen was clogged. Bought a fancy new stainless steel one for $400 from a marine supply in Baton Rouge. Friend finally convinced me to check the impeller clearance instead, and that was the whole problem. The old screen was fine, just had a half inch gap letting sand recirculate. Anyone else chase the wrong fix for way too long?
Ran into that same trap a few years back with a hydraulic dredge. Spent a month swapping out wear rings and seals before somebody pointed out the pump had a hairline crack letting air in. Always check the easy stuff first, even if it feels too obvious. Impeller clearance is one of those things everyone forgets about until it bites them. Good on your friend for helping you catch it.
It's the same with a lot of things honestly. People always want to blame the complicated expensive part first because it feels more like a real problem. Simple stuff like a loose connection or a dirty filter just seems too basic to be the issue so you overlook it until you've wasted a week.