Brand new bilge pump that doesn't pump.... ugh

Lancer28 · #1 (**permalink**) 02-03-2008

I've got a second issue today too. This one is stumping me.

I've got a brand new bilge pump installed and it takes 10-15 minutes of run time to re-prime it and get the water flowing out of the bilge each time I start it. Heck, sometimes it won’t prime and start to flow at all.

If I unclip the pump from the screen / mount and shake it, then the air bubbles slurp out of the hose and then it starts flowing. I've narrowed it to some sort of reverse-drain out of the bilge line to the overboard outlet, but even a rule self-priming pump isn't helping... ugh.

Obviously, I can't be below decks every time I need to run the pump to shake it to get started. The lift on the pump is only about 4 feet, and about 8-10 feet in length.

Is there anyway to resolve this - I've run out of ideas (well, besides scrapping it for a manual diaphragm pump I can run from the cockpit). I've replaced the hosing and pump, and I still haven't found a way to get the water out without dicking around with the pump itself each time it needs to run. The battery drain is a bear to deal with, notwithstanding the initial issue….

Some thoughts here would be GREATLY appreciated!!!!

k1vsk · #2 (**permalink**) 02-03-2008

Don't understand your statement that even a "rule self-priming pump isn't helping." All bilge pumps are self-priming so the q becomes with what are you comparing it?
There are only two reasons why a bilge pump won't work - too much head for the pump or a leak. What size pump are you using?

sailingdog · #3 (**permalink**) 02-03-2008

Have you checked how much voltage the pump is getting and how much current it is drawing. Maybe the motor on the pump is shot or it is drawing too little current to work properly. Either condition might leave the pump so that it can't self-prime properly. It could also just be a bad pump.

trantor12020 · #4 (**permalink**) 02-04-2008

Is your bilge clean? I know my Rule pump would have problem if my bilge is dirty with fibre, hair small pieces of small something. I even end up removing the strainer wire and cleaning the sloted base (red color bottom that mount on the bilge) before it would work.

MattGardner · #5 (**permalink**) 02-04-2008

This: " If I unclip the pump from the screen / mount and shake it, then the air bubbles slurp out of the hose and then it starts flowing"
...makes me wonder if there a backflow preventer on your bilge hose? If so it can trap a pocket of air that will compress below the (however many feet of) water in the bilge hose that will prevent the pump from working correctly.

sailingdog · #6 (**permalink**) 02-04-2008

Matt-

What you're thinking of is called a check valve, and they're usually a really bad idea on a bilge pump, since the add quite a bit of back pressure and really reduce the pump's output capacity.

Lancer28 · #7 (**permalink**) 02-08-2008

Awesome input guys, I would have never thought to look for a anti-siphon valve or whatever it is called.

I'll look into the amperage and voltage while I'm in there.

I'll touch base back here when I get the entire line checked and the power measured.. Heck, its a good excuse (for me to justify to the wife) to replace the older hose and electrical wires anyhow.

Thanks again