Jabsco Toilet Problem - Yes, Another One !

[Tequila]

Can anyone tell me why after i pump out my manual jabsco, the bowl should fill with water. I have replaced the valve in October. Any ideas out there

[svHyLyte]

Bad or over tightened Joker Valve allowing water in the discharge line to flow back into the bowl.

[Cotemar]

Tequila,

You have to replace both the Joker and Base valves.
See diagram here.

http://www.cruisersforum.com/forums/...tml#post226630

Mark

[svHyLyte]

Originally Posted by Cotemar

Tequila,

You have to replace both the Joker and Base valves.
See diagram here.

http://www.cruisersforum.com/forums/...tml#post226630

Mark

Mark--

You are correct of course. Note, however, that the base valve really only "seals" under the compression of the water as the piston is depressed. The same pressure that forces the water/waste out through the Joker Valve. At rest, the only thing holding the base valve down is the brass weight on the flap and it will allow water to flow back into the bowl. Less so, of course, with a new valve but eventually...

[Jetexas]

Regarding the OP's question, if I leave my switch in the "flush" position, I will eventually have water either leak or siphon back in -- it happens much faster under sail than it does sitting in the marina. Thankfully, it has never overflowed the toilet although I've found it dangerously close while the boat is heeled. If I flip it to the "pump dry" position after flushing, it won't back up. I was told this is standard for boat toilets. Whether or not that's true, I don't know.

I have another toilet question, recently when set to "flush" my toilet still pumps out but is no longer pumping seawater to actually flush the bowl. If someone made a mess in the bowl, I have to get a bucket of water and pour it into the bowl to get everything flushed down. Sometimes after pumping the bucket of seawater added to the bowl, it starts trickling seawater from the toilet as well, so I think it's a suction problem, not a blockage problem.

Any idea which valve or seal I need to replace to get it to start sucking seawater again, so that my guests don't have to embarrasingly come tell me that there's a mess in the bowl?

[svHyLyte]

Originally Posted by Jetexas

Regarding the OP's question, if I leave my switch in the "flush" position, I will eventually have water either leak or siphon back in -- it happens much faster under sail than it does sitting in the marina. Thankfully, it has never overflowed the toilet although I've found it dangerously close while the boat is heeled. If I flip it to the "pump dry" position after flushing, it won't back up. I was told this is standard for boat toilets. Whether or not that's true, I don't know.

I have another toilet question, recently when set to "flush" my toilet still pumps out but is no longer pumping seawater to actually flush the bowl. If someone made a mess in the bowl, I have to get a bucket of water and pour it into the bowl to get everything flushed down. Sometimes after pumping the bucket of seawater added to the bowl, it starts trickling seawater from the toilet as well, so I think it's a suction problem, not a blockage problem.

Any idea which valve or seal I need to replace to get it to start sucking seawater again, so that my guests don't have to embarrasingly come tell me that there's a mess in the bowl?

If the head and the intake are both under the water-line, you have the potential for a siphon unless you have a siphon break above the water line. These are problematical on the intake side of the head as the pump will simply pull air through the relief valve on the siphon break unless you have a means of closing that when you're pumping the head--we do, a tube connected to a small fitting on the side of the cabinet next to the head that one places one's thumb over when pumping the head.

As for drawing water in while you pump, the "Flush/Dry-Bowl" switch is really just a cam that when in the flush position holds the flapper valve over the raw water intake side of the pump open. It normally bears against a little bronze weight that is attached to the face of the flapper. Over time the weight can come loose and fall in and on top of the piston so that the flapper cannot be held open. The down stroke of the piston creates a vacume of sorts, holding the flapper in place and disallowing water to be drawn into the top of the pump cylinder. Instead, air is drawn around the lip-seal around the piston rod at the top of the pump. Alternately, the cam may have been damaged or broken (rarely) or the cotter pin holding the cam to the "Flush/Dry-Bowl" lever shaft wasted away so that the cam itself never moves despite the position of the lever. A rebuild is not difficult. Tedious perhaps, but not difficult. (Been there, done that...)

FWIW...

[Jetexas]

I do have a siphon break over the water line, so I'll put my finger over it and see what happens.

I replaced all the seals and valves in the toilet last summer at a cost of about $75, so I was hoping to be able to just service the one valve or seal that would suction the seawater in.

[svHyLyte]

Originally Posted by Jetexas

I do have a siphon break over the water line, so I'll put my finger over it and see what happens.

I replaced all the seals and valves in the toilet last summer at a cost of about $75, so I was hoping to be able to just service the one valve or seal that would suction the seawater in.

Jet--

If you have a siphon break in the raw water line between the thru-hull and the pump, the valve at the top of the break will not allow you to develop the vacuum necessary to draw water into the hose/pump. Note that if you have a Forespar vented loop you can replace the vented cap and duck-bill valve with a cap fitted with a barb for 1/4" hose and then run the hose to a convenient spot where it can be block for flushing but otherwise left open. See Vent Barb Assembly - Forespar MF 846* - *Vented Loops & Y Valves* - *Toilets, Parts & Accessories* - *Plumbing & Sanitation Other manufacturers have similar arrangements.

FWIW...

[cal40john]

Originally Posted by Jetexas

Regarding the OP's question, if I leave my switch in the "flush" position, I will eventually have water either leak or siphon back in -- it happens much faster under sail than it does sitting in the marina.

Your head on the intake side has two one way valves. Part 1350W from the link below are the two rubber flapper valves. They both open in the direction to let water into the bowl. Normally this happens when you push the pump handle down the top valve opens filling the chamber above the piston, then when you lift the handle the top valve is forced closed, the valve under it opens, and water goes to the toilet.

If your head intake through hull is forward on your boat it is facing forward. The lever in the flush position allows both valves to open. Moving the boat forward through the water pushes water up the intake line through both valves that are free to open and into the head.

I disagree with svHyLyte about the lever. When it is in the pump dry position, the lever holds the top valve closed. This is why the bowl tends to stay dry when the boat moves through the water. This also explains why many heads are hard to pump in one direction in the pump dry position as when you push the piston down you are creating a vacuum in the chamber. Some heads like the PHII have an air bleed for that.

John

http://www.raritaneng.com/pdf_files/...actIIv0502.pdf

[sneuman]

Originally Posted by Cotemar

Tequila,

You have to replace both the Joker and Base valves.
See diagram here.

http://www.cruisersforum.com/forums/...tml#post226630

Mark

Save the $ on the repair kit and buy a new toilet, but NOT another Jabsco. I have personally dealt with two of these problematic units on boats of mine and vowed a few years ago to spend the extra money to get a Raritan. I have not regretted it.

[svHyLyte]

Originally Posted by cal40john

...

I disagree with svHyLyte about the lever. When it is in the pump dry position, the lever holds the top valve closed. This is why the bowl tends to stay dry when the boat moves through the water. This also explains why many heads are hard to pump in one direction in the pump dry position as when you push the piston down you are creating a vacuum in the chamber. Some heads like the PHII have an air bleed for that.

John

http://www.raritaneng.com/pdf_files/...actIIv0502.pdf

John is correct in his explaination although his reference is to a Raritan rather than Jabsco head. (Both work similarly however.) In my commets I mis-spoke and said "open" rather than "closed" which is the correct order of operation. N'any case, the fix is not difficult, merely tedious.

[Seahunter]

Originally Posted by Tequila

Can anyone tell me why after i pump out my manual jabsco, the bowl should fill with water. I have replaced the valve in October. Any ideas out there

The joker valve needs to be replaced. (Installed in 1-1/2" housing at outlet) $10-15 and 10 minutes. Shop vac the head out first (it will suck the old joker valve inside but out don't worry).