Discharge pump runs but won't pump

[Fastlanefive]

I have a 1999 370 ac. About every time I try to use the sea land discharge pump it runs but won't pump out! I then have to take the hoses off and I will find the duckbill valves have been flipped inside out. I will then replace the duckbills and the pump will work fine for a time or two. I have talked to sealand and they thought I must have forgotten to open the seacock but I make sure each and everytime that is not the case. It has become a great source of frustration cuz each time I make a stinky mess to replace the duckbills. Would appreciate any help or advise! My discharge pump does not have impellers I am told, so a fried impeller can't be the issue. Help!

 

[techmitch]

That's a pretty $hitty introduction for a first post! Are you sure someone else isn't trying to make the boat take a dump with opening the butt plug first?

 

[flarepoman]

Throw it out and get one of these....:huh:

 

[Captain Allen]

I have the same problem and have been told that I might have pumped out the tank with the valve open, thereby reversing the duckbills. I really think it was the PO, but it could have happened.

 

[Dick Whetstone]

I had the same problem in my 270. When I disconnected the plumbing to get to the duck bill valves, one or maybe both were inverted. I replaced them and everything has been OK for three years. My guess is you or somebody (blame it on the first mate) either forgot to open the valve (which caused my problem) or you have an obstruction in the piping.