priming a fat sac pump?

I have an older fat sac pump that seemingly still works, I was able to fill my bag a week ago with it, with it dumped over the side of the boat. But now I cant get it to empty my bag. It will pump water in the intended direction, but I cant get it to prime when emptying the sac. I push down in the sac, get it as tight as I can... Im not sure waht is wrong here. It will prime when floating in the lake though. Maybe I just need to suck on it! lol!

Push on the sac harder. You're just not getting any water up to the impeller of the pump is my guess. Or you could, as you said, try sucking on it. lol

You...have...to...connect...the...pump...end...to. ..the...sac. Hee, hee, just kidding.

Check to make sure the pump is turning the correct way. An aerator pump will pump water in reverse, barely.
If that checks out, lift the other end of the hose out of the water until it primes. If you start the pump with the end of the hose in the lake, it has to be able to push out the captured air bubble. And that can be difficult for older pumps.
If it still won't pump, you probably need a new one.

I have found it difficult to prime dumping the sack if you have the hose in the water. Try pulling the hose out of the water while pushing on the sack. Having the hose in the water kind of air locks it and you have to push harder on the sack to compensate. I know it helps me.

Trying push it in deep, THEN powering it up.

We had one in our boat that would only pump one way, when I put the multi meter on it we found it was only pushing about 6 volts when spinning the motor in reverse but 12v to pump in, not sure why though.

Originally Posted by bmartin

Trying push it in deep, THEN powering it up.

yes, dont forget to pull out..

thats what she said...

Originally Posted by durty_curt

thats what she said...

"please prime me with your pump"