I'm helping my son get his beneteau 40, which he just bought, up and running. Both heads have an issue. They both "dry pump" fine but, when you flip the lever and try and wet flush (a) it doesn't draw any water on the upstroke and (b) it won't go down on the downstroke. It feels like it's compressing air. I flip it back to the dry flush position and the plunger goes down fine. Any ideas? (The through hull seacock is open.)
Head not drawing water
- Thread starter robinrjellis
- Start date
Is there a Y-valve in the system that directs effluent to the holding tank or overboard?
Hello,
The only problem I can think of is that the through hull for the water intake is closed or blocked by marine growth.
A (maybe) simple test would be to close the seacock on the head water intake line. Remove the hose for the water line at the toilet. First see if the plunger then works normally, with no resistance. If that works you can slowly open the seacock and see if water comes in. If it does then put the hose back on and try again. If no water comes in you can try to close the through hull, and try and clean out any blockage.
Good luck,
Barry
The only problem I can think of is that the through hull for the water intake is closed or blocked by marine growth.
A (maybe) simple test would be to close the seacock on the head water intake line. Remove the hose for the water line at the toilet. First see if the plunger then works normally, with no resistance. If that works you can slowly open the seacock and see if water comes in. If it does then put the hose back on and try again. If no water comes in you can try to close the through hull, and try and clean out any blockage.
Good luck,
Barry
Sounds like you have problem that's very common in Jabsco manual toilets--a failed wet/dry cam. The wet/dry "valve" is actually just a little "gate" (the cam) that the lever swings to block or unblock the flow of incoming flush water. Due to either a tooling or mfr'g flaw, it hangs up...creating back pressure that feels like pumping against a clog or blocked tank vent, except it only happens in one mode--usually the wet mode.
The cure: replace the wet/dry cam assembly…Jabsco will often send a replacement at no charge. However this requires taking the pump apart, which can be a nasty job if you haven’t been able to flush. I'd just replace the pump..that only requires removing and replacing a few hoses.
--Peggie
The cure: replace the wet/dry cam assembly…Jabsco will often send a replacement at no charge. However this requires taking the pump apart, which can be a nasty job if you haven’t been able to flush. I'd just replace the pump..that only requires removing and replacing a few hoses.
--Peggie
I have experienced this with Jabsco manual pumps. As Peggie suggested the easiest and I will add most reliable solution is to replace the pump.
I have fixed them a few times with varied results. There is a part similar to the attached picture. The little bronze discs get corroded. Quite sure the cam assembly referred to switches the discs. In a pinch you can take the top of the pump off, clean these up and it will work for a while. When reassembling snug the screws evenly, not tight. It is easy to warp or crack the top. Instructions can be found on-line.
I have fixed them a few times with varied results. There is a part similar to the attached picture. The little bronze discs get corroded. Quite sure the cam assembly referred to switches the discs. In a pinch you can take the top of the pump off, clean these up and it will work for a while. When reassembling snug the screws evenly, not tight. It is easy to warp or crack the top. Instructions can be found on-line.
I'm not sure why people are advising a pump replace/rebuild when a simple blockage is not ruled out? Is there something about the description of the problem that proves this is a failure of the pump? (I am not saying there isn't - I'm asking what I might have missed.)
I mean, I had a similar sort of issue with our head, once while at anchor which resolved when we were underway. So, I assume it was just a bit of kelp, in that instance.
I mean, I had a similar sort of issue with our head, once while at anchor which resolved when we were underway. So, I assume it was just a bit of kelp, in that instance.
There are no discs in a Jabsco wet-dry "valve" assembly. The "cam" consists entirely of a little "gate" that swings to block or allow the flow of the water. Cam failure has been a known issue for years.
Due to either a tooling or mfr'g flaw, it hangs up...creating back pressure that feels like pumping against a clog or blocked tank vent, except it only happens in one mode--usually the wet mode.
The cure: replace the wet/dry cam assembly…Jabsco will often send a replacement at no charge. However this requires taking the pump apart, which can be a nasty job if you haven’t been able to flush. Most people just opt for replacing the pump.
--Peggie
Due to either a tooling or mfr'g flaw, it hangs up...creating back pressure that feels like pumping against a clog or blocked tank vent, except it only happens in one mode--usually the wet mode.
The cure: replace the wet/dry cam assembly…Jabsco will often send a replacement at no charge. However this requires taking the pump apart, which can be a nasty job if you haven’t been able to flush. Most people just opt for replacing the pump.
--Peggie
My terminology maybe incorrect. The picture in my previous post is correct. Those round bronze things that look like discs corrode. Cleaning them with emery cloth can eliminate the symptoms described. I have never taken the time to analyze it but maybe the corrosion prevents the wet/dry switch from reaching full travel. I looked at the parts drawing on the xylem website but the detail drawing is not clear enough to see how they interact. The "discs" are part of key 21 "Top Valve Gasket" Here is the link. twist-n-lock-parts-list--2008-to-present.pdf