pvb
Well-Known Member
Also considerably easier to do.
Jabsco toilet filling back up...
- Thread starter Iain C
- Start date
Also considerably easier to do.
rogerthebodger
Well-Known Member
Now that is a very interesting arrangement and very little possibility of the holding tank being blocked.
Also if the pipe between the tank valve and the sea cock blocked the pumping arrangement would tend to force any blockage out of the sea cock unless it extreem.
Jungle Jim
Well-Known Member
I have replaced a joker valve and still had the original problem afterwards. It wasn't my boat so don't know if another one was tried afterwards or the whole assembly was replaced to resolve the issue.
P.s. wear wellies.
P.s. wear wellies.
Robin
Well-Known Member
Exactly, much easier than a rebuild, but you will also be able to do that with the old one at leisure and swap back when the job is needed next time. Having two Jabsco loos on board and living on board 24/7, we have accumulated a collection of rebuilt pumps ready to swap over if required but always have a few joker valves as well idon't doo the swap overs, but 'know a man who does' that can do it for a small fee much quicker than me.
Iain C
Well-Known Member
Hmmm...interesting. I've not used one of those before, but am I right in saying that the Twist n Lock effectively stops anything flooding back, so if the joker valve leaks again in the future it will stop anything coming back into the bowl? If that's the case then that is a bit of a no-brainer...
Easticks28
Well-Known Member
It appears so .
"Twist ‘N’ Lock action safety handle guards against flooding and waste backflow by locking the waste outlet valve shut. "
https://www.jabscoshop.com/files/MAN TWIST N LOCK toilets doc632.pdf
pvb
Well-Known Member
It helps to stop backflow, by pressing down on the base valve, but it doesn't guarantee to stop it! Jabsco say it "guards against" backflow. I've had backflow in my Twist'n'Lock toilet.
rogerthebodger
Well-Known Member
The problem with any flapper type NRV is that if any crud like calcium build up on the sealing surfaces will prevent the valve sealing properly .
As pvb says even with the pump plunger pressing down on the valve will not guarantee a water tight seal.
As pvb says even with the pump plunger pressing down on the valve will not guarantee a water tight seal.
Norman_E
Well-Known Member
In theory - yes
In Practice - No
The problem is that joker valves do leak, and what the twist and lock does is that it holds the flap valve down so as to seal the exit from the bowl. That is great in theory, but there are two pitfalls. Firstly the pressure from thepump rod extension pressing against the rubber flap valve can distort it, causing a leak. Secondly it relies for sealing on there being no scale on either the valve seat or the valve itself. I actually have quite a head of pipe from the heads outlet to the inlet at the top of the holding tank and have solved the issue in two ways. Firstly I converted to fresh water flush which reduces scaling. Secondly I fitted a Tru Design non return valve into the outlet pipe immediately after the heads outlet.
Momac
Well-Known Member
It is certainly working a lot better than the electric conversion pump that it replaced.
Graham376
Well-Known Member
Mate kept having problems with his Bav's holding tank. His cure was to block off the vent and pump until pressure blew the contents out. Last time he did it, the three quarters full tank split and took a few months to get rid of the results which slowly seeped down into the bilge. 
TheMerryFisher
Well-Known Member
I have the same issue on my Merry Fisher 805, my Jabsco is filling up but only when I am underway.
Is there a way to change the joker valve without closing the outlet sea cock from the toilet? I never thought to check it before and it's pretty stuck...lesson learnt!
Is there a way to change the joker valve without closing the outlet sea cock from the toilet? I never thought to check it before and it's pretty stuck...lesson learnt!
Graham376
Well-Known Member
Yes, depending on how much water you're happy with if it starts to syphon.
vyv_cox
Well-Known Member
Normally there is a loop of hose between the seacock and the joker valve, the top of which is above the water line. Removing the joker valve will allow the water in the upward leg of the hose to run out (if you are clever with a plastic bag you can catch it all) but the water in the downward leg will run into the sea. No water should flood into the boat.
paulajayne
Well-Known Member
Mate kept having problems with his Bav's holding tank. His cure was to block off the vent and pump until pressure blew the contents out. Last time he did it, the three quarters full tank split and took a few months to get rid of the results which slowly seeped down into the bilge.
Did it hit the fan?
TheMerryFisher
Well-Known Member
You are right about this, I had a little idea. At the top of my loop their is a valve that diverts waste water to the black water tank or out to sea. I thought that maybe if I diverted the valve this would have the same effect as closing the sea cock?
Graham376
Well-Known Member
From what he said, it went quite a distance. I often wonder if whoever bought it from Dickies can still smell it. Name begins with Toro.
Norman_E
Well-Known Member
The Twist and lock can actually make things worse because the piston rod extension presses down on the rubber flap valve and it it is not the perfect length the pressure distorts the rubber flap so tht it no longer completely seals. Its a great idea but in practice both the heads on my boat suffered from distorted and leaking flap valves because the rod pressed down just a little too far.