Stern seal problem maybe

[wp1234]

Having bought a new boat with extensive shaft corrosion (The survey picked it up) then having had the shaft replaced together with a new Radice axial RMTA type water cooled stern seal (installed by a marine engineer by the way). All looked OK until the boat went back into the water today only to find that the aft bilge in way of seal was filling with some water.
I should say here that in no way is the water gushing in but bilge isnt staying dry either. As I’m new to boating is it fairly normal to have a decent amount of water sloshing around the seal bilge or should it remain bone dry when alongside a quay wall? Do these seals bed in after a time and tighten up on the shaft. At what point does the water level become too much (apart from sinking of course) .
Thanks in advance

 

[MoodySabre]

I don't know the Radice shaft seal but from an earlier post it was described as being like a Volvo but re-engineered to include a water feed and a grease nipple. It therefore sounds as though it should be dripless - i.e. no water in the bilges at all. If it is dripping then either it has not been greased (if it has provision for that) , has been run when dry (or has insufficient water feed) and has worn or the shaft size and seal sizes are not compatible (25mm/1").

So don't accept wet bilges as you shouldn't be getting them and they will only get worse. If there is a problem jump on it. Get the engineers back in asap.

 

[pvb]

Spot on with your description! It certainly shouldn't leak.

 

[wp1234]

Thanks Moody and pvb .The one you have pictured is the one thats fitted for sure.It replaced the Volvo dry type on the old shaft.
I put grease in it myself on top of what the enginer had already put in so thats not the problem.I suppose there could be a problem with the water supply maybe, is there a certain water pressure thats needed to seal it to start with maybe, thinking here is that i've only run the engine at near idle so far .
I can see the water feed comes off the engine block but thats about all I know , is this something I can check myself ?
If there is no water getting to the seal will I have damaged it already , only moved the boat about 50 yds though.

 

[pvb]

Was enough grease injected? It needs about a fifth of a tube.

Did the engineer use the plastic shield when inserting the shaft? If not, the seals could have been damaged.

 

[wp1234]

Not sure if he used the shield for sure but it looks like he did since its pretty dirty and covered in grease. I sounds like I need him back in to check it all out if as you say it should not be leaking at all .I take it the only reapair that can be done is to take the shaft out again?

 

[MoodySabre]

Some water would get in the seal from the stern tube end so I don't think that you should have damaged it with so little use. Sounds like something is wrong with the installation.

Did they take the protective shield off once it was installed?

Good luck.

 

[Danny]

Just a thought - are you sure the water is coming in through the shaft seal? Might be worth checking the hose connections, etc. You could dry everything off and wrap some tissues around various places to see if there's any leak external to the seal.

 

[chwarae]

Check the jubilee clips,they maybe passing a little water. Thoroughly dry underneath the seal and put some tissue /toilet paper under the seal to establish where the water is coming from. Feel with your fingers. Check that the water isn't coming from something else and running down beneath the seal. I don't wish to teach my Grannie etc; but I recently had a similar problem with a new volvo seal and just had to tighten up the clamp on the rear of the seal.
Good luck.
H.

 

[Bilgediver]

.I take it the only reapair that can be done is to take the shaft out again?
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You make it sound like there is a steady flow of water but fail to say where this flow is coming from.???????

The water could be coming from either the clamp end or the shaft end or even from the water feed connection.???????

If the water is coming from the shaft end then it could be worth checking that the shaft seal is the correct one for the shaft. IE check thet you do not have a 1" seal on a 25 MM shaft.!!!!

It certainly seems that the engineer should be recalled and the problem found before it gets worse.

 

[wp1234]

thanks all for the great advice

 

[Eygthene]

Since the boat is new to you, it is possible that the seal/shaft area is not the source of the problem. On one boat I experienced a leak from a crack between the sterntube and the hull. This was due to the sterntube having suffered excessive rattle from soft engine mounts and vibration at certain revs. The solution was to cut out the sterntube and bond in a larger diameter one, thus eliminating the cracks, the leak and the rattle.