Vacu-flush pump on our 450 Sundancer

[DjDaoust]

Beginning this past weekend, our vacu-flush pump on the forward head continued to cycle without shutting down after a minute or so. Now it constantly pumps until I turn the Head switch off. Common sense tells me it's the duck valves need replacing. I tried the Dawn soap down the toilet trick, but didn't work. Any other possible solutions besides just replacing duck valves?

 

[Lazy Daze]

Does water stay in the bowl, or does it leak out?

 

[DjDaoust]

It stays, so I know the seal is good.

 

[Prosideus]

If it is constantly running, then it is never getting to a point of building a vacuum strong enough to disengage the pressure switch on the vacuum canister. Most likely your duck bills as you have mentioned. If it was cutting off for any length of time, duck bills would still be item number one on the list. Number two would be seals between bowl and head, number three would be flush ball shaft. Tied at number four would be leaking hoses, or faulty pressure switch in vacuum canister, or pump unit rebuild.

Good luck with getting option one remediated.


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[Lazy Daze]

It stays, so I know the seal is good.

I was hoping for the easy fix for you!

Even after being turned off for a while, does the system retain vacuum? Meaning, can you still get a good flush out of it after you turn the key off for a while - say 30 minutes?

Sometimes the pressure switch sticks in the "on" position as it gets older. If lightly pushing on the brass disc with your finger shuts the motor off, the problem is likely the switch. It's good to rule other things out before you get dirty and replace the duckbills. Not to say that it's one thing or the other - or that you shouldn't replace the duckbills as good PM, anyways.

 

[DjDaoust]

Thanks guys. Just checked with the marina and they said only $95 plus parts on replacing the duck valves, so I figured I'd start with that.

 

[Mike Blake]

That's what it is no question.

 

[Lazy Daze]

Thanks guys. Just checked with the marina and they said only $95 plus parts on replacing the duck valves, so I figured I'd start with that.

It could definitely be a couple of different things, but if you don't know when the DB's where changed last, you're due for them anyways. At $95, that sounds like money "happily" spent! And hopefully that takes care of it.

 

[Boatingnut]

If that pump is original, my bet is the bellows in the pump is either shot, or is in dire need of replacement. Rebuild the pump, as long as you are in there. Just my two cents.......

 

[Girlfriend III]

I did my duck bills last year. This year when I started the forward head up water was pumping out the top of the unit. Took it out and found the original bellow had cracked over the winter. $130.00 for the bellow and $58 for the "O rings, about 3 hrs. including taking unit out and cleaning and reinstalling. Nasty Job but it works now.

 

[Mike Blake]

I did my duck bills last year. This year when I started the forward head up water was pumping out the top of the unit. Took it out and found the original bellow had cracked over the winter. $130.00 for the bellow and $58 for the "O rings, about 3 hrs. including taking unit out and cleaning and reinstalling. Nasty Job but it works now.

Been there done that. I just had to change the seal in the toilet. It was easy and not to smelly