Took a 4 foot piece of pipe to my suction line and it saved me 2 hours of priming
Last Tuesday I was fighting a 6 inch dredge on a gravel bar outside of Twin Falls and the pump kept losing prime every 20 minutes. My old suction hose had a tiny pinhole leak I couldn't see, and instead of pulling the whole thing I wrapped a piece of inner tube around it with a hose clamp. Then I rigged a 4 foot chunk of PVC with a cap on one end to the primer port and just gave it one good pull of water before firing up. It hasn't lost prime in three runs now. Anybody else keep a capped pipe in the truck for stubborn intakes, or is there a better way to find those pinholes?
Had the same headache with a 4 inch on the American River last summer, losing prime every half hour and me cussing up a storm. Turned out it was a hairline crack right at the fitting, not even a pinhole, so the whole hose was done. What finally worked was pulling the suction line and filling it with water while the other end was capped, then watching for drips on the ground, found it in about two minutes. I've also heard of guys pressurizing the line real low with air and spraying soapy water on it, bubbles show up quick. Your capped pipe trick is smart though, keeping that water column in there beats sucking air all day.