Leaking top seal - Jabsco toilet pump

[CassidyNZ]

I’ve had a leak off the top of our one toilet pump which we’ve lived with for a while but when a friend replaced the whole pump to solve his same problem, I took his discarded pump to play with. I discovered that the stainless spring in the top seal is an insubstantial little thing with almost zero tension.

So I fished the spring out and looked for something to replace it. My first choice would have been an “O” ring but when I couldn’t find one of suitable size, my mind turned to a simple piece of tinned (to limit future corrosion) electric wire.

Cut to the right length and pushed down into the seal, it located perfectly in the groove intended for the spring and created a meaningful interference fit between the seal and shaft.

I’ve included a few pics to demonstrate the process, excuse the scribbles. I’ve done the discarded pump (which now resides in my spares locker) and also the leaker on the boat which has now been working for a month without leaking a drop.

I’ll report back should I get any leaks in the future but in the meantime members with the same problem that don’t want a second mortgage on their home to replace the pump, should try this. It’s a simple job.

[JPA Cate]

Hey, good job! I like the use of tinned wire, that's a nice touch.

The problem can also be addressed with an O-ring....which there are kits so you can glue up your own to match where they have to go.

Ann

[Jim Cate]

Good fix, but that seal is readily available at any bearing/seal shop, and costs around 2 bucks here in expensive Oz. When you purchase the new one, ask the vendor to replace the spring with an o-ring. This is a common modification and the shop (if in any area near salt water) is likely to be familiar with it. Adds a few cents to the cost.

I keep a few in our pump repair kit.

Jim

[billknny]

I am all for saving money, but this is an awful lot of work to save a few pennies.

The kit with ALL the seals and maintenance parts for this toilet is US$20, the entire pump replacement assembly is US$85.

How much is your time worth? I'll make a wild guess that the time spend on this McGyver job could have been better spent on projects with more substantial returns...

Oh, and every boat really should have a kit for making whatever size o-rings they need. They are cheap and easy. Custom O-ring Kit

[Jim Cate]

The kit with ALL the seals and maintenance parts for this toilet is US$20, the entire pump replacement assembly is US$85.

Dunno about NZ, but here in Oz I paid nearly 200 bucks for a replacement pump, and the parts kit is around 75... and few chandleries carry them, so a tedious custom order is often required with added shipping costs and delays.

As I said, the shaft seal costs around 2 bucks and the installation is pretty quick... maybe ten minutes the first time, less thereafter. And further, it's a repair that you can make in remote places with small parts carried on board. Seems good practice to me...

Jim

[kas_1611]

Check the shaft for microscopic damage, a good magnifying glass will do, as it is easily marked or roughened during servicing. Especially if gripped with pliers or pipe wrench. I wrap a few wraps of PTFE Tape (plumbers mate) around the shaft before gripping it with anything during servicing of my pump and never had a problem with the top seal leaking in nearly 10 years (and have never changed the top seal o-ring either).

[Brewgyver]

Originally Posted by billknny

I am all for saving money, but this is an awful lot of work to save a few pennies.

The kit with ALL the seals and maintenance parts for this toilet is US$20, the entire pump replacement assembly is US$85.

Custom O-ring Kit

The major U.S. chandleries get $70-80 for the rebuild kit, making replacing the entire pump assembly pretty attractive.

I've seen lots of posts here and on other forums that people are having to rebuild or replace that pump just about every year, and that would have me thinking about going to another head altogether. My boat came with a Groco HF, and I've had to rebuild it once in six years, but of course I'm not living aboard. I imagine, too, boats that are mothballed every winter may play a part in the short useful life of these things.

[SV Bacchus]

I had the same issue in Grenada, bought an Oring for $2US and replaced it. Once I had the Oring it was a 5 minute job including cleanup and putting the tools back.

Mine may be a different model/year as it had an Oring and not a spring.

[CassidyNZ]

Originally Posted by billknny

I am all for saving money, but this is an awful lot of work to save a few pennies.

The kit with ALL the seals and maintenance parts for this toilet is US$20, the entire pump replacement assembly is US$85.

How much is your time worth? I'll make a wild guess that the time spend on this McGyver job could have been better spent on projects with more substantial returns...

Oh, and every boat really should have a kit for making whatever size o-rings they need. They are cheap and easy. Custom O-ring Kit

Firstly, it’s not an awful lot of work, maybe 20 minutes all in and given I’m a retired person with 9 hours a day for projects large or small, I don’t place a lot of value on 20 minutes.

Secondly, in NZ we don’t get the kind of prices for stuff that you do in the US. See attached images clipped directly from the local chandler’s website.

Thirdly, doing repairs like this is good practise for when you’re in places like Vanuatu or the Marshall Islands where the likes of Jabsco pumps or kits are not held in stock by the local grocer.

Fourthly: like I said, I have an O-ring set but there were none of the size needed. The set is more or less still complete since over the last ten years I may have used perhaps 5 or 6 parts. Don’t see the need for another O-ring kit that will take locker space and never get used.

For the record, how many O-ring applications do you have on your boat? How many have you actually made in the last year with your custom kit?

[Doug Rutherford]

I think that this solution is one of ingenuity. Yes, there may be cheaper and or better solutions to this problem but this is an alternative for when you may not have a kit available. We all need to be self-sufficient and think out solutions for ourselves. Well done and thank you for your simple solution.

[CassidyNZ]

Originally Posted by kas_1611

Check the shaft for microscopic damage, a good magnifying glass will do, as it is easily marked or roughened during servicing. Especially if gripped with pliers or pipe wrench. I wrap a few wraps of PTFE Tape (plumbers mate) around the shaft before gripping it with anything during servicing of my pump and never had a problem with the top seal leaking in nearly 10 years (and have never changed the top seal o-ring either).

I think often the wear on the seal is due to abrasive content in the seawater being pumped (sediment). I have a pump in the second head on my boat that is now at least 12 years old (was there when I bought the boat) and, like yours, it also doesn’t leak. Who knows what causes these things. The spare pump I did the “modification” on is just 4 years old, original on a Beneteau of the same age.

Also on both the pumps I’ve just repaired, the handle that is removed to get the top flange off the shaft came off by hand, no tools required.

[Kerry1]

Been there.... I looked on this site for answers to the exact problem you had. So yes it's here like most other solutions to our boating needs. I used a factory seal kit which didn't last long. Then I ended up buying cheap seals and installing one of them, perfect fit for a couple of bucks. But, the seals didn't have the necessary stainless tension spring and so, despite coating them with water resistant stuff- they failed pretty quickly. In the end I bought a whole new pump assembly, now it's good again.

I think the problem is the shaft wears, or get's scored and nothing (cheap) will then sort it out. Ultimately I think it's a design problem, those seals are good (and intended for) for a rotational movement rather than lateral. I notice that in the old bulldozer type water pumps (piston type), on the piston shaft where it enters the bore, they use a packing type gland with a tension nut to contain the leaks, and it needs periodic tightening or replacement after so long. I wonder if that would be more suitable than a little seal. I actually tried back to back seal replacements, hoping a double seal would do it- nope.