Jabsco toilet not pumping in

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Duffer

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I've had the same problem every couple of years and I thought I would cure it by buying a new twist n lock pump. That was 2 years ago and now I've got the same problem of not pumping in and very little resistance on the pump. I am guessing it is the O ring on the piston rod. Is this easy to replace and do you need the whole service kit or just this part? Any tips/advice appreciated!
 
My 7 year-old RM toilet has been known to do the same thing when left for a few days.

The temporary cure was to pump vigorously for several seconds until it primed & started to work. The longer term solution was to put a good splash of cooking oil in the bowl, give a few strokes to get it into the pump and leave for a couple of hours. It needs redoing a couple of times a season
 
I believe that if the Joker valve does not close properly then the pump may fail "pump in", so it may be worth while (not pleasant) to remove the valve and clean it.
Some of the parts are available as seperate items, mainly the larger bits, the smaller bits are included in the service kits.
http://www.jabscoshop.com/marine/ma...0-manual-twist-n-lock-toilet-compact-bowl.htm

At a cost of just over £23 for the kit, it may be worth purchasing. They sometimes crop up on ebay for much less
 
Thanks for that. The diagram looks a little different to the older (non- twist n lock) pumps:

http://www.jabscoshop.com/marine/ma...0-manual-twist-n-lock-toilet-compact-bowl.htm

There seems to be an upper seal assembly available for £5 odd (part 18) and also a lower O ring (part 30) for £1 odd. Alternatively there is a piston rod O ring assembly at £13 (part 29) or a complete new pump at £53 all ex vat and delivery.

Any tips on which to replace for this problem of poor or not pumping in appreciated. There is some clean water returning to the bowl despite the twist and lock feature.
 
It's usually caused by the flap valve with a weight that is supposed to lower it. If the loo is left in the "dry" position for long periods the rubber stiffens in the up state and when it fails to drop you can't pump. If you have sea-cocks closed, have a syphon-break or are out of the water, it may be better to leave the loo in the "wet" setting when the flap will settle and be usable more quickly.
 
Stemar said:
My 7 year-old RM toilet has been known to do the same thing when left for a few days.

The temporary cure was to pump vigorously for several seconds until it primed & started to work. The longer term solution was to put a good splash of cooking oil in the bowl, give a few strokes to get it into the pump and leave for a couple of hours. It needs redoing a couple of times a season
Click to expand...

Thanks for that and I do the same but I think there is more to it this time (i.e. I already tried that and it didn't work so I think one of the seals needs attention).
 
It may help to study the drawings of a toilet valving on my website here. The joker valve is part of the discharge side and has no effect on the water inlet. If the bowl pumps out correctly it seems unlikely that the piston O-ring seal is at fault, as the same seal does both jobs. By far the most likely cause is that the fresh water inlet valve is being held open by something, which what happens during the 'bowl empty' setting. It often occurs that something is not quite square so that the valve does not seat properly, or of course there could be a foreign body present.

I see that johnalison has posted the same suggestion while I was writing mine, although he gives an alternative cause.
 
Last edited:
Duffer said:
Any tips on which to replace for this problem of poor or not pumping in appreciated. There is some clean water returning to the bowl despite the twist and lock feature.
Click to expand...

In that case, strip it down, clean and inspect all parts, the defective part may then be obvious. I would suspect the joker valve or the top gasket valve. If the piston O ring was knackered, I doubt if the unit would pump out.
 
vyv_cox said:
It may help to study the drawings of a toilet valving on my website here. The joker valve is part of the discharge side and has no effect on the water inlet. If the bowl pumps out correctly it seems unlikely that the piston O-ring seal is at fault, as the same seal does both jobs. By far the most likely cause is that the fresh water inlet valve is being held open by something, which what happens during the 'bowl empty' setting. It often occurs that something is not quite square so that the valve does not seat properly, or of course there could be a foreign body present.

I see that johnalison has posted the same suggestion while I was writing mine, although he gives an alternative cause.
Click to expand...

I was under the impression that if the joker valve did not close properly during the upstroke of the pump piston, then the suction of the pump on the inlet side would be affected
 
nigel1 said:
In that case, strip it down, clean and inspect all parts, the defective part may then be obvious. I would suspect the joker valve or the top gasket valve. If the piston O ring was knackered, I doubt if the unit would pump out.
Click to expand...

Many thanks for those replies which are coming in thick and fast. I'll look into it tomorrow and see if I can get to the bottom of it. It certainly gives me something to go on.
 
nigel1 said:
I was under the impression that if the joker valve did not close properly during the upstroke of the pump piston, then the suction of the pump on the inlet side would be affected
Click to expand...

The upstroke is surely the delivery stroke on the inlet ???

If the little flap valve does not seat properly when in the flush postion the inlet section of the pump does not function. Just blows and sucks through it.
 
nigel1 said:
I was under the impression that if the joker valve did not close properly during the upstroke of the pump piston, then the suction of the pump on the inlet side would be affected
Click to expand...

Nope, joker valve has nothing to do with it. It's a very simple pump; as vyv_cox suggested, a look at the diagrams might help people understand how it works.
 
VicS said:
The upstroke is surely the delivery stroke on the inlet ???

If the little flap valve does not seat properly when in the flush postion the inlet section of the pump does not function. Just blows and sucks through it.
Click to expand...

Hi Vic,
this is where I got my info from, and it makes sense to me. The lady in question is regarded as quite an expert on marine sanitation systems.

http://www.cruisersforum.com/forums/f115/electric-to-manual-toilet-pump-help-72646.html#post831736

Go to last post
 
Not Joker valve...

though it's always worth giving that a scrape/squeeze/twist to break off any calcite build-up.

On ours it was also "usually caused by the flap valve with a weight that is supposed to lower it" that's the rectangular one shown on the left of the picture of the service kit in the website link. You can effect a temporary cure/improvement by cleaning off any calcite deposits and then boiling it for a minute or two in water - don't use a good saucepan or you will not be popular - but certainly in Greece you can buy them seperately rahter than a complete service kit; we saw some in a Chandlery priced at €2.25 each (we assumed a cock-up) so bought five!

If want a piston ring/seal, you can get these and indeed the shaft seal (where it passes through the top cap) from any decent bearing/seals Factors for about 30p each, which is a site less than the genuine Jabsco ones
 
nigel1 said:
I was under the impression that if the joker valve did not close properly during the upstroke of the pump piston, then the suction of the pump on the inlet side would be affected
Click to expand...

If that was true the flush water would not work if the bowl was empty. Clearly this is not the case. Other than the double-acting piston there is no connection between the fresh and foul sections of the toilet. Either will continue to work if the other fails.
 
pvb said:
Nope, joker valve has nothing to do with it. It's a very simple pump; as vyv_cox suggested, a look at the diagrams might help people understand how it works.
Click to expand...

From looking at the Jabsco drawing, and having overhauled a few myself, I would say that the only valve at the base of the pump is the one that allows the foul water into the pump during the upstroke, as vyv cox calls it on his drawing, the "foul water suction valve". Its my take on the Jabsco system, that the Joker valve is the foul water discharge valve. If the joker valve does not properly close, whenever suction is applied below the pump piston, it will tend to take suction from both the toilet bowl and from sea.
 
nigel1 said:
From looking at the Jabsco drawing, and having overhauled a few myself, I would say that the only valve at the base of the pump is the one that allows the foul water into the pump during the upstroke, as vyv cox calls it on his drawing, the "foul water suction valve". Its my take on the Jabsco system, that the Joker valve is the foul water discharge valve. If the joker valve does not properly close, whenever suction is applied below the pump piston, it will tend to take suction from both the toilet bowl and from sea.
Click to expand...

Sorry, that could well be "your take" on it, but it's incorrect.
 
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