Intake to Raw Water pump issue

[Safeseas]

Hi All,

Would appreciate some valuable help.....

Whole story short;
MD2030 on 33 foot sailboat

Had a small leak in engine bay bilge ( salt water ) after cruising that increased to an undesirable amount. not too much but surely noticeable

Checked the raw water pump weep holes and there was water exiting that area, so I changed the seal at back of impeller ( including small gasket / o-ring; one behind it onto shaft ) and once at it, I changed the impeller, even though it was changed 6 months ago. Then after also inverting the plate cover the water stopped weeping from the weep holes, so I thought the problem was solved but not;

I noticed that there is a small leak ( could have been there ) coming up from the hose where it is connected to the raw water pump ( bottom part ). This hose in my engine comes from the back from the gearbox and from the gearbox then there is another hose to the strainer and then to the seacock. I therefore decided to change this part of the hose, the one that goes from bottom of raw water pump to gearbox ( i.e. feeding hose ), I replaced it and added 2 jubillee clips on both sides but the part onto the gearbox is ok..no leaks but the part onto the raw water pump is still leaking. When engine is off with seacock open there is a slight leak but when engine is on, the leak increases.

I appreciate any help on this please. Thanks to All

The attached photo shows the type of raw water pump before I changed the impeller and hose etc

 

[PabloPicasso]

Is the hose not sealing onto the. Pump nipple/spigot? If that is the case check the following;

No burrs or debris on the nipple/spigot. Clean if there is

Is the hose correct size?

Try warming the end of the hose in boiling water for a bit before attaching and clamping it. An insulated mug is ideal for this.

Good luck, and do let us know how you get on.

 

[Safeseas]

Is the hose not sealing onto the. Pump nipple/spigot? If that is the case check the following;

No burrs or debris on the nipple/spigot. Clean if there is

Is the hose correct size?

Try warming the end of the hose in boiling water for a bit before attaching and clamping it. An insulated mug is ideal for this.

Good luck, and do let us know how you get on.

Thanks for your reply, I fitted 2 jubilee clips instead of 1, should one of them be on the nipple at the edge? as I don't think I did so...The hose is abit different ( since I did not take out the original one before buying) I had bought it in case something like this happens but it was a tight fit, infact on the gearbox side I had no leaks...I will now take the old one and check exactly at the shop ...will surely let you know outcome.

 

[Safeseas]

Any other valuable feedback is much appreciated thanks again

 

[pete]

Sometimes 2 clips can cause more trouble than they are worth if the spigot isn't over long and shouldn't be necessary to make a good seal, the second clip is just a backup. Check the spigot is clean and not cracked or split, is the leak coming from the front cover gasket? There should be hardly any pressure here so sealing should be easy if the hose is a reasonable fit.
Try blowing up the pipe and getting someone with a bottle of soapy water to look for bubbles at the same time.

 

[Safeseas]

Sometimes 2 clips can cause more trouble than they are worth if the spigot isn't over long and shouldn't be necessary to make a good seal, the second clip is just a backup. Check the spigot is clean and not cracked or split, is the leak coming from the front cover gasket? There should be hardly any pressure here so sealing should be easy if the hose is a reasonable fit.
Try blowing up the pipe and getting someone with a bottle of soapy water to look for bubbles at the same time.

Hi Thanks for your feedback, the leak is coming out from the pipe edge with the raw water connection...indicated as per attached photo on old pipe....I should check the spigot, but the jubilee clip is to be tightened on the flat part of the raw water pump part not on the spigot? ( to clarify ) and maybe I use only one jubilee clip...the hose is way over long as I pushed it in quite firmly....thanks again

 

[pete]

Hi Thanks for your feedback, the leak is coming out from the pipe edge with the raw water connection...indicated as per attached photo on old pipe....I should check the spigot, but the jubilee clip is to be tightened on the flat part of the raw water pump part not on the spigot? ( to clarify ) and maybe I use only one jubilee clip...the hose is way over long as I pushed it in quite firmly....thanks again

Might be worth cutting a couple of inches of the end of the pipe and trying again if the pipe is over long and try one clip slightly further down the pipe if the spigot is long enough. It looks like it should be an easy one to seal but being a heating engineer all my life I have repaired leaks only to eventually find the leak was actually higher up and running down.
Good luck.

 

[Safeseas]

Might be worth cutting a couple of inches of the end of the pipe and trying again if the pipe is over long and try one clip slightly further down the pipe if the spigot is long enough. It looks like it should be an easy one to seal but being a heating engineer all my life I have repaired leaks only to eventually find the leak was actually higher up and running down.
Good luck.

Thanks a lot for your feedback, just to clarify, the clip has to sit on the neck not on the edge/nipple ( that's how I made it )

 

[Tranona]

You do not need 2 clips. The spigot is designed so that the hose stretches over the nipple at the end and a single clip is used on the flat part. The water is not under much pressure at this point. The hose should be 19mm ID

 

[Safeseas]

You do not need 2 clips. The spigot is designed so that the hose stretches over the nipple at the end and a single clip is used on the flat part. The water is not under much pressure at this point. The hose should be 19mm ID

Thanks

 

[dansaskip]

It might be worth changing the hoses for new one. Old ones do lose their flexibility and sealing properties at spigots after a while. I have just changed all my hoses when I realised how old they were. I went for silicone rubber hoses - (search online) more expensive yes but superior to either plain rubber or what you sometimes see clear plastic with crisscrossed reinforcing.

 

[Safeseas]

It might be worth changing the hoses for new one. Old ones do lose their flexibility and sealing properties at spigots after a while. I have just changed all my hoses when I realised how old they were. I went for silicone rubber hoses - (search online) more expensive yes but superior to either plain rubber or what you sometimes see clear plastic with crisscrossed reinforcing.

Thanks

 

[S04]

Nothing to do with the problem I'm sure but the impellor blades seem to be wrong. The one on the cam suggests clockwise rotation but the blade two to the left (going clockwise) appears to be bent for anti-clockwise rotation. I'm just puzzling how that might be unless of course the impellor has just been fitted and has not been rotated.

 

[Safeseas]

Thanks all for your valuable feedback, some updates....changed both hoses,top and bottom of raw water pump and all is OK no water in the engine bay ...yeah. I cut abit the edge of the new hose as suggested above.....thanks.....


One last question..I replaced the hose at top of raw water pump that goes to siphon since it was also part of the leak issue.... the existing one was thinner internal/external diameter and infact was frail, I replaced with an internal diam 19 hose (alike bottom one) that seated well with no leaks...do you think I replace with a new thinner one at first chance or it should not be an issue?...thanks all again

 

[Safeseas]

Nothing to do with the problem I'm sure but the impellor blades seem to be wrong. The one on the cam suggests clockwise rotation but the blade two to the left (going clockwise) appears to be bent for anti-clockwise rotation. I'm just puzzling how that might be unless of course the impellor has just been fitted and has not been rotated.

Agreed when installing the new one I now made sure that it's all in a clockwise rotation now tnx

 

[Safeseas]

Thanks all for your valuable feedback, some updates....changed both hoses,top and bottom of raw water pump and all is OK no water in the engine bay ...yeah. I cut abit the edge of the new hose as suggested above.....thanks.....

One last question..I replaced the hose at top of raw water pump that goes to siphon since it was also part of the leak issue.... the existing one was thinner external diameter and infact was frail - the inner diameter is 19 also I presume as I replaced with an internal diam 19 hose (alike bottom one) that seated well with no leaks...do you think I replace with a new thinner one at first chance or it should not be an issue?...thanks all again

 

[LittleSister]

I can't see it's an issue. It is of sufficient size to accommodate the water flow, and it fits the hose tails on the pump and other end properly, so it's fine.

I've no idea why the other one would have been smaller internal diameter other than random variations in manufacturing or between metric vs. imperial sizing.

 

[Safeseas]

I can't see it's an issue. It is of sufficient size to accommodate the water flow, and it fits the hose tails on the pump and other end properly, so it's fine.

I've no idea why the other one would have been smaller internal diameter other than random variations in manufacturing or between metric vs. imperial sizing.

Thanks