what to try next

Fred

Active Member
Oct 3, 2006
308
Jersey Shore
Boat Info
2005 390 Sundancer
thruster, ST7001 autopilot, tracvision M3, Raymarine Dual E120, 7.3 Kw Kohler
Engines
8.1sHO with V-Drives
My head system is inoperative. There is no vacuum at the head but my vacuum generator is producing vacuum showing a green light, ready to flush. I proved vacuum at the vg2 by pulling the vacuum switch out which turns the pump on and then will build vacuum again when the switch is replaced shutting down as expected. For that reason I feel the duck bills are ok, am I correct in assuming that? There is no visible clog at the head.
What would you check next?
 
My head system is inoperative. There is no vacuum at the head but my vacuum generator is producing vacuum showing a green light, ready to flush. I proved vacuum at the vg2 by pulling the vacuum switch out which turns the pump on and then will build vacuum again when the switch is replaced shutting down as expected. For that reason I feel the duck bills are ok, am I correct in assuming that? There is no visible clog at the head.
What would you check next?
Sounds like you can have a clogged line somewhere between the head and the accumulator tank!
 
Have you tried a plunger? Even if you can't see a clog it could help move something along.

I've also heard of people pushing a garden hose into the system (while on) to flush any obstructions.
 
I'm thinking the same thing but so far I have used a plunger and not been able to clear it.
 
I'm thinking the same thing but so far I have used a plunger and not been able to clear it.

So you do have standing water in the bowl and down into the lines? If not the plunger likely wont be effective. Though if you do have standing water the garden hose idea would be less than ideal :)
 
The suction on the other side of the clog could be working against the plunger. Had similar issue but clog was close to the bowl was. Tried plunger with no luck as the suction on the other side was holding it in place. Fortunately (or unfortunately) was able to reach a hand in there to remove it. As soon as it moved a bit the suction caught it and pulled it through. Not sure how but if you are able to break the suction in the line you may be able to use a plunger?
 
My understanding is to never use a plunger. It’s possible to invert your duck valves....or so I’ve been told
 
I don't have standing water but I'm sure I can create that scenario. I can release the vacuum at the accumulator tank and plunge and I have also tried this with slight success. When I re introduced the vacuum I then had a slight vacuum at the head but that soon fully clogged again.
I have a plastic fish tape I can try from the head down if that is even possible. I don't know.
 
I don't have standing water but I'm sure I can create that scenario. I can release the vacuum at the accumulator tank and plunge and I have also tried this with slight success. When I re introduced the vacuum I then had a slight vacuum at the head but that soon fully clogged again.
I have a plastic fish tape I can try from the head down if that is even possible. I don't know.
I've seen where the paper and what ever was like a rock !
I would try pulling the hose off the head ( a thankless job ) and with a wet vac try and remove it in that direction. You would first have to drop what ever vacuum is on the system
 
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I have successfully used this in my 340. But I also got a hose valve that was right before the attachment. I turned on the water from the dock pedestal with the valve closed. Turned on the vacuflush. Then stepped on the toilet flush to open the bowl, inserted the rubber attachment and then turned on the hose valve. The rubber attachment expanded, blocked the bowl and pushed the clog free. Only kept the water on for a few seconds as not to over pressurize anything. Worked well.
 
To follow up I cleared the clog today. I had to remove the 90 degree pipe that goes to the vacuum tank. I found it totally clogged with paper. There was no way this would ever dislodge without taking it apart and if it did it would have surely clogged the duck valves.

I think I will stop using West Marine paper as it appears to be thicker than the Scott's we use at home. I'm going for the Sealand stuff from now on.
 
We use Scott’s rv and marine paper from Walmart. Works like a charm.
 

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