Is an external water pump feasible?

[chal]

My water pump is probably leaking water into the engine (see my thread on that at http://www.ybw.com/forums/showthread.php?t=310291 )

Because parts are so expensive for the engine in question (a pretty ancient Albin AD21) and because I'm reluctant to spend a lot on an engine I'm probably going to have to either replace or rebuild fairly soon, I am wondering if it would not be better to just remove the pump, or at least disconnect the water pipes from it, and use a separate electric pump to push water through the cooling system.

This would be simpler, faster and cheaper than trying to repair the engine pump. It only needs to run while the engine is on so the alternator would supply plenty of power for that.

Is this feasible, at least as a short term remedy? I have the spec for the capacity of the pump so could get an electric one that met or even exceeded it.

 

[prv]

Can't see why not. People do similar with fuel pumps.

Pete

 

[Tranona]

Yes, it is quite feasible. There used to be an aftermarket kit to convert raw water cooled Yanmars to fresh water using an electric pump. Not sure how an electric pump would deal with seawater, although it is not hot. An alternative might be a belt driven pump from a crankshaft pulley, which is what is used as a raw water pump on some Yanmars, rather than gear driven.

 

[chal]

Thanks for the replies!

Would there be any problem with leaving the old pump well alone and just disconnecting the hoses? It won't seize up or anything not having water running through it?

 

[Tranona]

You might want to take the impeller out and seal the ports. Are you sure it is the pump? as your symptoms sounded like something far more serious than just water leaking from a seal.

 

[PaulGooch]

Yup, as said, a belt driven pump. If the bottom pulley has a spare V you could use that, or fit it so the drive pulley lines up with the alternator belt and fit a longer belt.

http://www.jabscoshop.com/marine/pumps/bronze-engine-cooling-pumps/

 

[DAKA]

My water pump is probably leaking water into the engine (see my thread on that at http://www.ybw.com/forums/showthread.php?t=310291 )

Because parts are so expensive for the engine in question (a pretty ancient Albin AD21) and because I'm reluctant to spend a lot on an engine I'm probably going to have to either replace or rebuild fairly soon, I am wondering if it would not be better to just remove the pump, or at least disconnect the water pipes from it, and use a separate electric pump to push water through the cooling system.

This would be simpler, faster and cheaper than trying to repair the engine pump. It only needs to run while the engine is on so the alternator would supply plenty of power for that.

Is this feasible, at least as a short term remedy? I have the spec for the capacity of the pump so could get an electric one that met or even exceeded it.

An electric pump which circulates enough water pressure isnt going to be cheap either.

I think you need to start posting good quality photos and measurements of required seals etc

many of us will have spare parts which we are not likely to every use and will be happy to post them to you for beer tokens or possibly free.

 

[PaulGooch]

An electric pump which circulates enough water pressure isnt going to be cheap either.

I think you need to start posting good quality photos and measurements of required seals etc

many of us will have spare parts which we are not likely to every use and will be happy to post them to you for beer tokens or possibly free.

Looking at the other thread though Pete, the OP is complaining that the seals and impeller are a whopping £50. The impeller alone for mine is almost £40.

That doesn't look especially over the top to me, compared to other pump spares. £900 for a new pump is a bit OTT though.

 

[DAKA]

Looking at the other thread though Pete, the OP is complaining that the seals and impeller are a whopping £50. The impeller alone for mine is almost £40.

That doesn't look especially over the top to me, compared to other pump spares. £900 for a new pump is a bit OTT though.

Yes I realise that, my impeller is listed at £99
but jabsco and ebay have the more suitable neoprene much cheaper, I also have loads of spare second-hand ones from several previous boats kicking around that may or may not fit .
each time I renovate a pump there are loads of good serviceable parts left over.

He clearly wants to do this for peanuts , it takes time but without photos/dimensions he has no chance.

He might be better on PBO forum .

 

[chal]

He clearly wants to do this for peanuts

I'm really not just being mean, there is simply no money left in the kitty right now, and I have to be extra careful not to throw good money after bad as well. Because the boat is primarily sailed and the engine probably only runs for a mile or so up river when the wind is awkward I'd like to nurse it along for now if I can until I have sufficient funds to do it properly.

I take the point about photos and will try to take some next time I am at the boat and I'm also grateful for the various offers of possible cheap parts, as well as the advice and information.

I'll try to get the pump off and take it from there.

 

[VicS]

I'm really not just being mean, there is simply no money left in the kitty right now, and I have to be extra careful not to throw good money after bad as well. Because the boat is primarily sailed and the engine probably only runs for a mile or so up river when the wind is awkward I'd like to nurse it along for now if I can until I have sufficient funds to do it properly.

I take the point about photos and will try to take some next time I am at the boat and I'm also grateful for the various offers of possible cheap parts, as well as the advice and information.

I'll try to get the pump off and take it from there.

You've asked a question about a saily boat on the Mobo forum

They dont recognise engines smaller than 10 zillion horse power

 

[PaulGooch]

You've asked a question about a saily boat on the Mobo forum

They dont recognise engines smaller than 10 zillion horse power

Anything less than 150 HP is a generator, surely ?

 

[DAKA]

You've asked a question about a saily boat on the Mobo forum

They dont recognise engines smaller than 10 zillion horse power

Oh yes we do

Its a 2 stroke engine (similar to my chainsaw )

 

[PaulGooch]

I'm really not just being mean, there is simply no money left in the kitty right now, and I have to be extra careful not to throw good money after bad as well. Because the boat is primarily sailed and the engine probably only runs for a mile or so up river when the wind is awkward I'd like to nurse it along for now if I can until I have sufficient funds to do it properly.

I take the point about photos and will try to take some next time I am at the boat and I'm also grateful for the various offers of possible cheap parts, as well as the advice and information.

I'll try to get the pump off and take it from there.

Wasn't being rude or suggesting you are mean, we all know about budgets.

What i really meant was, changing to an external pump to save £50 wouldn't be practical as the external pump would cost much more than that. If yours is totally kaput, an external pump would be cheaper than £900 for a new one.

 

[chal]

Wasn't being rude or suggesting you are mean, we all know about budgets.

No, that's fine, I know you're not, and I am really grateful for all the advice (you replied to my first post as well) as although I have stripped and repaired an engine it was many years ago (and I didn't have a bad back then either!) and it was a petrol engine that was in a car. I have no experience of marine diesels at all really and freely admit that I'm looking for shortcuts that I know are not ideal but will tide me over for the time being.

Anyway, thanks again for your help and I will see what I can do next time I have a chance to do some work on it

 

[aquatom]

If you are going to fit an electric pump it would be advisable to wire it through a relay which is switched from the oil Pressure switch so it only runs when the engine is running or you may accidentally fill your exhaust up with water!

 

[Dave_Seager]

As has already been said, the price for the impeller at about £30 is fairly typical. The two seals are about £10 each which is a bit steep. However, fitting a complete new pump will cost far more than £50 and involve the risk of further complications.

The original Albin pump is an unusual and clever design as it is actually two pumps on the same shaft. The front one handle the raw water. The rear one circulates the fresh water on a fresh water cooled engine. On a raw water cooled engine it acts as a motor-drive bilge pump and there is a small bleed hole between the two pumps to stop it from drying out.

If you engine is fresh water cooled then you cannot simply fit one new pump as you suggest. If it is raw water cooled, do you plan to buy a replacement bilge pump too?

I think that it would be unwise to modify the engine just to "save" £50.

 

[Divemaster1]

Oh yes we do

Its a 2 stroke engine (similar to my chainsaw )

Quite similar to my 2-strokes then

 

[Divemaster1]

Having read the origina thread and this one, it sounds like you may be lucky if the pump seal is the problem as it sounds like the volume is too high and getting through to the rocker cover through the valve lifters which implies that water may be flowing into the combustion chamber ........ but I would definetly try the simple things first as the tend to be somewhat cheaper than the big jobs....