# Jabsco macerator pump not pumping just whinning.



## SanDiegoChip (Jun 12, 2007)

Hi,
Jabsco macerator pump not pumping just whinning. No whinning please!
We have installed a new VacuFlush toilet and holding tank. All new hoses and hose clamps. We have the hoses coming from the top of the holding tank to the macerator and then to the pump out deck plate which has a O ring. I did tape it closed also so it would not suck air with blue tape. There is not a valve after the macerator. There is a 5\8 vent hose from the tank to outboard. We used the original macerator that was on our 1978 Islander Freeport. There is a valve on the through hole that the macerator pumps to.
We open the valve and the macerator whines just fine. But it never pumps out anything. I tried to rebuild the macerator impeller and housing but the new one ended up freezing up and then when I loosened the housing to pump bolts the impeller disintegrated. My guess is that it was the wrong kit. Any way I put the old impeller and housing back on and tested it in a pale of water and it pumps out water. I did leave the new cutter plate on.Then I reinstalled it. When we go to the pump out station it pumps out fine (not using the macerator). Could I not have the macerator nots tight enough? There are four nuts holding the pump parts to the motor. I have tried different tightening amounts. The tank I am trying to pump out is 31 gal and the tank is half full. I have checked the through valve the macerator pumps out to and it is clear to outside the boat. There are not any obstruction in the housing.
Could the macerator be leaking in air where the impeller housing connects to the electric pump?
The deck plate has an O ring which I replaced but am nut sure if it is the original size. I taped it shut. Would I still need a valve after the macerator to deck plate? The people who sold us the toilet said no.
Why would the macerator not pump out from the holding tank?
Thanks,
Chip
1978 Islander Freeport


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## SanDiegoChip (Jun 12, 2007)

*Ok Jabsco says I do not need a valve*

Ok Jabsco says I do not need a valve. They say it must be an air leak. I will re-check that.
Chip


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## rikhall (Feb 7, 2008)

SanDiegoChip said:


> Hi,
> We have the hoses coming from the top of the holding tank to the macerator


Chip

Does the top outlet (where you have the hose to the macerator pump) have a "tube" so that the pump sucks from the bottom of the tank?

Rik


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## donradclife (May 19, 2007)

Where is the pump located in relationship to the liquid level in the tank? Its best if it is below. The macerator pumps are advertised as self-priming, but with a bit of wear they aren't, and that's a real PITA given what you are pumping...that's why we went to a hand-diaphragm pump for emptying the holding tank.


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## Volkhard (Feb 19, 2006)

I second donradclife's comment. My pump did a similar thing and I couldn't figure out what was going on, so I redid the whole system from head over holding tank all the way to the fittings. while I installed a manual vacuum head (LaVac) for simplicity I installed a holding tank (sealand) with all connectors at the top (like yours) but installed a manual diaphragm pump to empty the holding tank. works like a charm and doesn't need electric, switches, breakers, rebuilding kits. Just one easy to replace spare part the rubber diaphragm. Just look at your system, perhaps you are able to simplify as well.


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## SanDiegoChip (Jun 12, 2007)

Our Jabsco pump is above the top of the tank. I will try moving it, it is a rather hard to get at of course. Problem then is waste would sit in the hose as the pipe out from the tank goes throug the top of the tank. 
I like the idea of the hand-diaphragm pump, I am trying to find a place for it.
Thanks
Chip


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## SanDiegoChip (Jun 12, 2007)

Yes the tube comming out of the top of the holding tank is a pvc type tube that goes to the bottom of the tank, about a inch or so off the bottom with a slice of it so it will not clog.


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## SanDiegoChip (Jun 12, 2007)

I tried taping all the connections to the pump for air leaks and it just wines.


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## mitiempo (Sep 19, 2008)

You said it is an older macerator. Maybe it's worn enough not to get good suction. From your description there is not a valve after the macerator. Do you mean it goes directly to the through hull? Where does the hose to the deck plate come from? I've fixed enough macerators to not want one myself. A hand pump is a more reliable idea. By the way the manual Lavac pump is described by the manufacturer as a pump that shreds the waste like a macerator and never clogs or has the issues of a macerator and they're correct. The same type of manual diaphram pump would work for you. Even a large holding tank would only take a few minutes to pump out manually.
I was planning a larger holding tank as mine is very small and have decided to build a gravity tank in the back of the closet opposite my head. New deck plate above the outlet through hull for easy unclogging if it's ever an issue but from what I have read it shouldn't be.


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## SanDiegoChip (Jun 12, 2007)

There is a deck pumpout that goes to a T which one part of the T goes to the holding tank the other part of the T goes to the macerator. The macerator has an out that goes to a through hole valve. That is the only valve. The macerator is higher than the holding tank. The holding tank has a pipe going through the top down to the bottom of the tank.
The Jabsco macerator was a factory install in 1978 and is original. I do not know if it actually ever worked. It worked for me when I took it out and tested it in a bucket. My next test will be taking the deck pump out hose off the T and taping it up. That way I can see if there is an air leak there if it works of course. 
I went over the idea with my wife about a hand pump and she was not liking the idea. I am in good shape at 63 but there is the chance she would have to hand pump out the gray water and she was not liking the idea. She is not a wimp as she wet vacked out our old Catalina 30 holding tank when we installed new hoses. This boat has a bigger holding tank 18 verses 31 gal. Any way I can understand her and will honor her here. So that means either fixing this Jabsco macerator so it could be used as a back up or use it and buy a new one as a back up. Either way I got to know if it will work. If I cannot get it to work I will buy a new one and try it. All else fails I will install a SaniPump™ Discharge Pump from Dometic. It makes sense because it is the same as the vacume pump we have for the toilet. Just need to get something working before I can move forward on the decisions. 
I also had another idea to try. I propped up the hose that is attached to the pipe that goes into the top of the holding tank so it would not sag. It could be producing an air leak where the pipe goes into the tank. 
I will be trying these things in the next couple days and will post the progress.


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## mitiempo (Sep 19, 2008)

Are you putting grey water in the tank as well? Make sure all the connections are airtight. You say there may be a problem at the top of the tank. With good hose and hose clamps (2 if there is room) the seal should be airtight. The three connectiona at the T should also be perfectly sealed. Airtight also means no odors. Good luck.


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