Waste pumpout priming

[ric992]

My pumpout discharge works sometimes and not other times, I can always hear the pump running though. Is there something that needs to be done to get the pump primed or wait til it's basically full?

 

[Lazy Daze]

No, it should just work.

When it works, does it evacuate everything? Meaning, have you physically checked the level in the tank (use a flashlight right against the side of the tank).

What type of overboard discharge pump do you have? There are different styles and different "problems" comes with each.

And... just in case... are you familiar with the overboard discharge rules?

 

[ric992]

Yes I am familiar with the rules. When it works in does empty completely and can hear it start to bubble air under the boat. I will add a picture of my pump

 

[ric992]

Possible that I should not empty it all the way, when I use it?

 

[Lazy Daze]

No, emptying it completely is fine.

Will wait on pics.

 

[ric992]

This is the pump

 

[Lazy Daze]

OK, that style is basically the same thing as your vacuum pump but with only 2 duckbills instead of 4. This pump setup is commonly referred to as a T-pump as opposed to the vac pump which is an S-pump (transfer vs suction).

-- Since it does evacuate everything, it's very unlikely that there's a problem with the dip tube in the tank... although there's still a very small chance there's a crack in it.

-- The most likely scenario is that the pump just needs to be rebuilt.

 

[ric992]

Ok thank you, I will replace the pump

 

[ric992]

But there is a separate pump just for the toilets, correct?

 

[ric992]

If I loosen the valve for the actual pumpout as if you were going to pump at a fuel dock while it's turned on it is blowing air out of the opening

 

[Lazy Daze]

Ok thank you, I will replace the pump

Note that I didn't say "replace" the pump. Rebuild.

 

[Lazy Daze]

But there is a separate pump just for the toilets, correct?

Correct - re-read what I wrote above in post #7.

 

[ric992]

I did and thank you, I see now

 

[Lazy Daze]

If I loosen the valve for the actual pumpout as if you were going to pump at a fuel dock while it's turned on it is blowing air out of the opening

I don't understand what you're saying.

Your overboard pump-out does not and SHOULD NOT be used while at a dock. That is a violation of the overboard discharge rules.

 

[ric992]

Yes I know this, when out away from dock in the proper area. I opened that valve to try and get it to prime and it did not work. I just let me know the pump is working, but just moving air

 

[Lazy Daze]

Yes I know this, when out away from dock in the proper area. I opened that valve to try and get it to prime and it did not work. I just let me know the pump is working, but just moving air

OK, it was confusing also because of this: "If I loosen the valve for the actual pumpout as if you were going to pump at a fuel dock"

I'm not sure I get what you're saying. To do a pumpout at the pump-out station, there shouldn't be a valve to open... just unscrewing the deck plate, right?

 

[ric992]

Yes, I meant deck plate opening. Tried to get that to help prime

 

[Lazy Daze]

Ah, OK. Now it makes sense.

That's good thinking to do that. You really shouldn't have to do that, though. Your tank might be new enough that you also have a "tank saver" (older tanks didn't) which is basically a one way valve on top of the tank (nothing would be connected to it). Take a look - see if you have that.

 

[Jaybeaux]

If he opened the deck plate while the overboard seacock is open and the discharge pump is pumping, I would have thought that air would be getting sucked in through the deck plate, just like the vent through the charcoal filter works.

Jaybeaux

 

[ttmott]