Jabsco Twist N Lock woes

[MikeBz]

Jabsco pump stopped pumping water in yesterday. Pumping out working fine. Checked the seacock was open and no blockage. I had a service kit at home so took the pump home and dismantled it. One of the flap valves (is that the correct term?) in the top valve gasket had fallen apart, so I cleaned everything up, fitted the service kit & reassembled following instructions with the kit and various YouTube videos. Refitted it to the boat today and it still doesn’t pump in, but worse when you try to pump in water dribbles and squirts out from the interface between the valve cover and the pump cylinder (part names from Jabsco’s own pare parts list). Took it apart and double-checked everything, reassembled - same problem.

The only thing I could think of is that the top valve gasket is too thin and not making a seal, but checked it against the old one and it’s no different. So I’m stumped. Looks like I’ll just buy a whole new pump but I’d like to know why this is happening.

 

[ash2020]

Isn't it horrible when you find a fault, fix it and it still doesn't work! I feel for you. I can't picture the exact pump but is it possible to submerge the whole thing in the sink and see if air is getting in or out of the sealing gasket?

 

[MikeBz]

Isn't it horrible when you find a fault, fix it and it still doesn't work! I feel for you. I can't picture the exact pump but is it possible to submerge the whole thing in the sink and see if air is getting in or out of the sealing gasket?

It might be tricky. I did wonder whether to try pressurising it, but given that water gets out I’m pretty sure air will.

 

[Boater Sam]

Jabsco's plastic pump parts distort with age and once you have undone them they will not seel unless you restore flatness to the mating surfaces by rubbing them on abrasive on a piece of flat glass or a surface plate.

 

[johnalison]

I’ve taken them apart and not generally had trouble. Providing everything is the right way round and all that, it is mainly a matter of making sure that everything is properly lined up and evening out the tension without overtightening. A little silicon grease can help finally seal things.

 

[nevis768]

Its much easier to buy the pump as a unit, its not much dearer and no farting about, excuse the pun...
Jabsco Toilet Pump Assembly | Force 4 Chandlery

Make sure you get the right age

 

[Dockhead]

Its much easier to buy the pump as a unit, its not much dearer and no farting about, excuse the pun...
Jabsco Toilet Pump Assembly | Force 4 Chandlery

Make sure you get the right age

That's the correct answer.

If you must use this horrible toilet, simply keep a spare pump on hand and swap it out in whole. The ONE AND ONLY virtue of this device, is that it's cheap as chips, and therefore, disposable.

For very reasonable money you can buy a Chinese Seaflow electric pump, highly regarded, which slots in where the manual Jabsco went. That would be my solution. You can keep the Jabsco manual pump as a backup.

 

[MontyMariner]

Is the In / Out leaver operating correctly?

 

[MikeBz]

Is the In / Out leaver operating correctly?

Yes pretty sure.

As I said in my first post, I’ll just buy a whole new pump but I’d like to know why this is happening.

Electric flush toilets? Having experienced the din they make on a charter boat no thanks.

 

[Lightwave395]

I gave up trying to 'service' Jabsco loo pumps years ago - spawn of the devil..., since then I've replaced the pump with another new one every 3 or 4 years in effect as a preventative maintenance job.
My new boat has an electric loo which I viewed with suspicion when I bought it, yes it's a bit noisy but my OH is very happy with it, TBH so am I.
One thing I learnt in days gone by is was don't try and replace the jabsco pump with a cheaper chinese copy - I don't know if I was somehow doing it wrongly but it didn't 'quite' fit and the price difference was much in the comfort scheme of things.

My J44 from some years back had Raritan tolets - faultless in my 4 years of ownership but seldom seen here

 

[wonkywinch]

I serviced mine which had never really worked properly.

There was rust on the motor shaft around the bearing/rubber gasket and even after using the service kit to replace it, still leaked.

I ended up replacing the whole thing to fix the leak.

 

[Stemar]

From experience, it's possible to reassemble the pump with the lever in the wrong place. It doesn't work, but I can't remember which way it's supposed to be, just that it's not the way I assemble it the first time

It's even possible, if you're tired and stressed enough, to put the gasket/valve the wrong way round or upside down. It doesn't work.

 

[dunedin]

That's the correct answer.

If you must use this horrible toilet, simply keep a spare pump on hand and swap it out in whole. The ONE AND ONLY virtue of this device, is that it's cheap as chips, and therefore, disposable.
.....

Actually I find the manual Jabsco toilet pumps to be simple and reliable.
Never had any issue with servicing except the messy aspects.

Buying a new pump every time is slightly more expensive. But certainly quickest and easiest is to swap every 2-3 years, depending on usage. If cost a priority the optimum is swap in a new or serviced pump, and then service the removed one later ready to swap in next time.

I don’t believe a more complex electric pump can reduce the servicing (10 mins every 2-3 years if swap) and certainly increases the failure points.

 

[Sianna]

Yes pretty sure.

As I said in my first post, I’ll just buy a whole new pump but I’d like to know why this is happening.

Electric flush toilets? Having experienced the din they make on a charter boat no thanks.

Thats what I ended up doing after taking the old one apart to try and fix

 

[Dockhead]

Actually I find the manual Jabsco toilet pumps to be simple and reliable.
Never had any issue with servicing except the messy aspects.

Buying a new pump every time is slightly more expensive. But certainly quickest and easiest is to swap every 2-3 years, depending on usage. If cost a priority the optimum is swap in a new or serviced pump, and then service the removed one later ready to swap in next time.

I don’t believe a more complex electric pump can reduce the servicing (10 mins every 2-3 years if swap) and certainly increases the failure points.

Depends on how much you use the boat. If more than a couple of months a year, the manual ones don't last that long, in my experience. But more than that, they work badly. And because it's so laborious to pump through enough water to clear the lines completely, usually the don't get cleared, and you end up with calcium build-up in the lines.

This is where an electric toilet shines. Dramatically reduces the risks of clogging due to maceration right at the toilet, easy to pump through enough water to completely clear the lines. There's nothing really to service in them -- the impellers outlast the rest of the device; I've never replaced an impeller.

I have a Jabsco electric conversion in my forward (guest and day) heads, with backup manual pump. First years with this boat there was a Jabsco manual one, which is where I have my unhappy experience with them. Previous boat had a Raritan manual one which was much better.

A few years ago I converted my aft heads to a Planus fresh water electric toilet, which is really good, albeit expensive, and the installation was a nightmare project which took many weekends. Flushing with fresh water completely eliminates calcification, is brilliant when you're using a holding tank, eliminates smells.

 

[dunedin]

Depends on how much you use the boat. If more than a couple of months a year, the manual ones don't last that long, in my experience. But more than that, they work badly. ….

Not my experience - and based on 3-4 months on board per annum for past decade or so.

 

[vyv_cox]

We had a Jabsco Lite for many years. Very labour intensive. The root cause of its problems was the very low flush volume, intended not to fill holding tanks too quickly. As a result the scale build up was horrific - I was cleaning the joker valve monthly and the impeller about twice per season. Eventually it needed a new shaft seal, which only came as a unit with a motor, more expensive than a manual Jabsco toilet. So it was dumped and replaced with a manual one.

In two full seasons the bog standard one needed no extraordinary maintenance whatsoever.

 

[Plum]

Jabsco's plastic pump parts distort with age and once you have undone them they will not seel unless you restore flatness to the mating surfaces by rubbing them on abrasive on a piece of flat glass or a surface plate.

Not in my experience, but then my jansco hears is only 26 years old

 

[MikeBz]

I remembered today that I had an old Jabsco pump from a previous boat in the garage which had failed (I don’t remember the symptoms) many years ago. I bought a service kit for it at the time but then decided to buy a new pump and apply the service kit to the old one and keep it on board as a spare. Well the latter part of the plan never happened, hence I had decided to dig the kit out yesterday apply it to the pump which failed the day before.

Brought the “serviced” water-spurting pump home last night and today made a hybrid of its top cover/piston assembly and the old cylinder from the garage. All assembled identically to before - if I block the inputs/outputs and pump then I get persisting pressure or vacuum depending on the orientation of the lever. So it seems as though it’s not leaking. Back to the boat to refit tomorrow- if it’s still no good then it’s bin time and buy a new one.

When dismantled, both failed pumps had shed the rivet holding one of the brass (?) discs to the top valve gasket.