Water leak

[Mccraci]

I found quit a lot of water under the engine this morning. I have spotted water dripping from the sea water pump.
Has anyone ever had this issue in the past.
I tightened the hose clamps it made no difference.
Is the pump given to leaks?

 

[Mccraci]

Sorry a Nanni T4.155

 

[Portofino]

The seals , that’s the rubber bit from the impeller house is made of rubber .To keep this ring which wraps around the shaft tight , the rings got a metal spring in it .
Over time it corrodes , what ever protection say it galvanisation breaks down .Now rusty it weakens , it cant press the rubber up and seawater starts to drip .
You should inspect what’s called a weep hole and when it weeps do a seal replacement.( plenty of u tube vids )

How ever if the spring snaps then water gushes out .This is where it sounds you are now .
Get a rebuild kit its DIY .
They are all pretty similar.
I just did one on my geny last week …..noticed a weep .

 

[penfold]

Sea water pumps can leak; they're generally made by Johnson or Jabsco and failure of shaft seal is quite likely what has happened to yours. You can replace the pump if you're feeling rich or if not repair the pump by replacing the seal(possibly also the shaft and/or bearings as they may be contributing to the failure).

 

[Tranona]

The seals , that’s the rubber bit from the impeller house is made of rubber .To keep this ring which wraps around the shaft tight , the rings got a metal spring in it .
Over time it corrodes , what ever protection say it galvanisation breaks down .Now rusty it weakens , it cant press the rubber up and seawater starts to drip .
You should inspect what’s called a weep hole and when it weeps do a seal replacement.( plenty of u tube vids )

How ever if the spring snaps then water gushes out .This is where it sounds you are now .
Get a rebuild kit its DIY .
They are all pretty similar.
I just did one on my geny last week …..noticed a weep .

While you are correct that the water is coming out of the witness hole because of seal failure it is highly unlikely that it is because the springs have failed because of "galvaniation breakdown" (whatever that means) because they are stainless. It is normally the lips of the seal wearing through use and maybe grit in the water or the seal wearing grooves in the stainless steel shaft.

Make sure the replacement seals have stainless springs as OE replacements will. If buying generic seals then ensure they have stainless springs and not carbon steel which will rust (nothing to do with galvanic action)

 

[simonfraser]

More likely to leak again with grooves in the shaft ?

 

[Portofino]

While you are correct that the water is coming out of the witness hole because of seal failure it is highly unlikely that it is because the springs have failed because of "galvaniation breakdown" (whatever that means) because they are stainless. It is normally the lips of the seal wearing through use and maybe grit in the water or the seal wearing grooves in the stainless steel shaft.

Make sure the replacement seals have stainless springs as OE replacements will. If buying generic seals then ensure they have stainless springs and not carbon steel which will rust (nothing to do with galvanic action)

A failed spring it fractures because of corrosion, they all do cause a gush , bilge filling as reported . Even SS eventually goes ,the seawater will find that crevice , just last longer obviously.
A weep is the rubber interface integrity, maybe age and plane wear or a bit of abrasive substance scoring the shaft .

Wether it needs just the seal , a full rebuild or indeed a whole whole pump won’t become apparent until it’s post mortem .
Its a serviceable part .

What I meant was the spring might be NONE stainless steel but some other metal that’s been galvanised and it’s protective cover the galvanisation has broken down allowing seawater to corrode said area = it weakened it it fractures and the rubber seal pressure is no more = your bilge starts to fill .

Yes of course refit if possible a SS sprung seal .But in todays Far East outsourcing , e bay vague descriptions , there’s a very good chance desirable as it it’s finding a totally SS one , even one in OEM packaging is going to be problematic.

My geny one ( Johnson ) lasted 7 yrs since I last did it , FWIW , so it’s not too bad what ever material it was lasted long enough.
It had corroded and snapped btw .

 

[Mccraci]

Does anyone know the difference between a Nanni 970311169 and a Nanni 970311169b seawater pump.

 

[Paul1962]

Good Afternoon,
I had a Beneteau Antares 7 which had the Nanni T4.155. The sea water pump on these is basically a Johnson F6B-9 - 10-24515-01 which I think you could probably only buy from Nanni.
However, the "innards" of the pump can be sourced from Johnson or from any reputable seal/bearing supplier. Get rubber shielded bearings though.

I understand the Johnson service kit 09-46693 includes the Impeller and the 2 seals. You would be wise to give the whole pump a service including the bearings.

Hope that helps

 

[Mccraci]

Thanks
Do you know anyone that supplies the service kit.
09-46693

 

[V1701]

I have an F5B & got a rebuild kit from a company in Germany. ASAP Supplies in the UK didn't have the kit & wanted something like £16 just for the little rubber lip seal. If you can correctly identify the correct lip seal they're usually about £3. The company in Germany has lots of kits for different pumps - see here...

I would add that mine just needed the lip seal replacing, was able to do it just by removing the cover, removing the impeller, hooking out the old lip seal & pressing in the new one (make sure you get it the right way round)...

 

[oldgit]

For the really parsimonious.
If the pump has a wear on the shaft where it mates with the original seal and if perhaps a new shaft is either not easily available or costs a fortune, it is possible as temporary repair, to fit new seal but do not drive fully home in the seal housing , few mm less could possibly position the seal on a new bit of unworn shaft.