Jabsco Head O Ring Exact Size ?

[MarkJ]

Hi folks.

I am NOT paying $70 for the Jabsco head service kit!!

I just want the O ring... in fact I need 2 O rings.

I took one of the old ones into a shop in Malaysia and they sized it and gave me a replacement but its not exactly correct and clean water comes out the top of the pump handle on the upstroke.

Does someone know the correct size O ring so I can take it to a shop here and get the correct size?

Thanks so much.



Mark

[rg500]

why not just get an O-ring splicing kit?....comes in a plastic box with 3 or 4 different diameters, 2or 3 feet in length. complete with glue, cutter, splice jig etc. make your own for years to come.

[Jim Cate]

G'Day Mark,

Interesting -- on our Jabsco manual head (model 29120-2000) the pump shaft seal isn't an o-ring, but a small lip seal (29044-2000)... also available from non-Jabsco sources for far less than their price. So, are you sure that yours is sealed with an o-ring? Maybe a different model... who bloody knows???

Good luck and confusion to our enemies (rapacious OEM people).

Cheers,

Jim and Ann s/v Insatiable II

[GordMay]

Which model head, and which seal?

[MarkJ]

Its OK Gord. I am just going to buy the whole new pump. Its only double the price of the service kit and will make the whole head look much better.

Anyone coming to Turkey in the next few weeks could buy me the whole toilet at Westmarine for LESS than I am paying just for the friggin' pump.

Ahhhhh don't it make the Economists glow.

[svHyLyte]

Mark--

The failure of the Lip-Seal at the top of the pump assembly is very common. The "spring" inside the seal corrodes. I believe you can obtain replacements for that seal only from JABSCO. I have found that packing the seal with silicon based water-proof grease (ie non-petroleum which seems to attack the rubber of the seal) significantly prolongs the life of the seals. We get severa years between replacements even in the warm water of southwest Florida.

The trick to installing the lip seal is to completely remove the pump, remove the top valve assembly from the cyclinder assembly so that you can slip your fingers into the cyclinder bore, drop the piston all the way into the cycliner so that you can reach the top of the piston rod, "glue" the lip seal (lips facing out) to the end of your finger with a little grease, than, gingerly, slip the seal over the top of the piston rod, spinning the seal in the right direction so that the lip winds down the threads to the unthreaded portion of the piston rod (which prevents damage to the lip as it passes over the threads). Then, carefully manipulatie the piston to pass the rod through the hole at the top of the cyclinder barrel which will allow you to slide the seal up the piston rod into place with two fingers. Your piston should have a wide rubber or nylon bushing on the top face that will bear against the face of the lip seal and fully seat it without damaging the lip. It's a bit of a pain in the neck but it can be done. If you cannot find a replacement o-ring (I could not) you can make a substitute by loading the grove in the edge of the piston with beeswax. Just ensure you have lubed the cyclinder bore (I use SailKote). As you pull the piston into place the beeswax compresses into the grove and will make a satisfactory seal as you really don't have all that much pressure. A friend of mine suggested using waxed seazing twine rather than plain beeswax but I've not tried that although it might work juat as well.

In future, do not pull the piston up so much that it "bottoms out" against the face of the lip seal and resist the temptation to lube the piston rod with anything that might attack the lip seal--for example vasoline, commonly found in heads, which will attack the rubber in the seal.

FWIW...

[anjou]

If you get stuck Mark, and you know which O ring it is, ie part no, etc, then I can soon pop one in a jiffy bag and mail it to you.

[MarkJ]

Originally Posted by svHyLyte

Mark--

The failure of the Lip-Seal at the top of the pump assembly is very common. The "spring" inside the seal corrodes.

FWIW...

Sensational advice!! Thanks so much!! I seem to remember that spring not feeling perfectly correct.

And 'FWIW' you advice is worth heaps Thanks

Originally Posted by anjou

If you get stuck Mark, and you know which O ring it is, ie part no, etc, then I can soon pop one in a jiffy bag and mail it to you.

Thanks for that lovely offer. I'll buy the whole pump and that will fix the most obvious 2 problmes the leak, and the appearence. The old one looks old. Old in a head looks dirty.


Thanks


Mark

[anjou]

Last year in Sardinia I had a O ring in the VW common rail diesel pump die on me and with lots of local assistance I tried to order one.
It was probably only a £2 ring but all the main dealers kept telling me I had to buy the whole fuel pump @ 450 euros.
What a rip off. Sr Pinna, the marina owner very kindly helped translate into Italian and did his best to explain but he was also convinced it was a cartell stitch up, so we went into the workshops and he gave me a tube of liquid gasket.

The O ring sat in a groove, so I cleaned it out and injected the liquid in, let it set and reassembled the pump.

It worked fine and got me back to UK and is still in there now after another 9,000 miles.

There is ALWAYS a way to get things fixed up. Never be ransomed. Thats the inspiration to prove them wrong and find a way out of a tight spot.

[anjou]

As a comparrason, this afternoon Ive just ordered a Jabsco 12v, electric flush toilet for £295.00.
Sometimes it seems, the sum of the whole unit costs less than all the individual replacment spares.

[MarkJ]

Originally Posted by anjou

Sometimes it seems, the sum of the whole unit costs less than all the individual replacment spares.

YUes, its that colusion you mentioned. It sux!!

[Jd1]

I know this is an old thread but I have what I think is an O ring issue as well - When the cylinder has air in it after having set a while, it feels as if air bypasses the o-ring until water starts to flow and everything gets working fine. I have found an o-ring locally (50 cents! as compared to about $10) but it is noticeably harder than the o-ring from a service kit which I have on the boat. I would rather leave the full kit alone of I just need to replace the o-ring. So, question .... has anyone experienced problems with an aftermarket o-ring? I am concerned about stiffness of the pump and possibly accelerated wear on the pump cylinder.
As a side note, the replacement o ring is part# G11-N70-324, Nitrile o-ring. he bill does not give dimensions but if anyone is interested, I can measure it. The material is sandard o-ring hardness (whatever that is) and the Jabsco ring is softer than what is normally 'standard' for o-rings.

[Cruisingscotts]

Orings are made out of all sorts of material, EPDM nitrile, Buna, viton etc, they also can have different hardness. There is no standard. They do depend on a amount of crush to properly seal. All will be either standard or metric.

here is a good site with lots of O-ring info

Material Selection : The O-Ring Store LLC, We make getting O-Rings easy!

"most" lip seals are measured in MM, outside diam x inside diameter x thickness, they come in single lip and double lip configurations, they also can be steel, rubber coated and with a SS spring.

here is one large US manufacturer

SKF Seals

[peghall]

Oh for Pete's sake! Once upon a time Jabsco built a decent toilet for the money. Today all their toilets (and everything else as far as I know) are build in Mexico with parts from China and other offshore countries.

Jabsco prices their "service kits" at almost the price of a new pump for a reason: they don't wanna sell kits, they wanna sell pumps. They---regrettably like most companies today--build acheap "disposable" toilet...so when it needs a part, either replace the pump or replace the whole toilet with one that has life expectancy of longer than 15 minutes! Believe it or not, there are a couple of mfrs left who build 'em.

[Jd1]

Originally Posted by peghall

Oh for Pete's sake!
<snip>
either replace the pump or replace the whole toilet with one that has life expectancy of longer than 15 minutes! Believe it or not, there are a couple of mfrs left who build 'em.

It wasn't Pete's shift so he had nothing to do with it

Would you give suggestions to those of us not specializing in this subject matter please ?