Replace Penta MD17D sea water pump with an electric?

[Snoz]

Is it possible to replace the existing sea water pump (which is leaking) with an electric pump on my Volvo Penta MD17D engine?

The current setup I have is a fresh water/coolant in header tank, through gear box, through sea water pump, through heat exchanger & thermostat, through Keel cooling and then returns to top of header tank. This works well but last trip I noticed coolant in the bilge and pressure testing of the system revealed the sea water pump is leaking.

I can't seem to find any information on if it can or should be done or what would the specs for the electric pump.

Cheers,

Andrew.

[belizesailor]

Theoretically I suppose, but why? What are you looking to improve upon? You are not likely to find any specs for an electric pump for this use because this would not be a typical instalation.

Also, you state that coolant flows thru the sea water pump....you mean fresh water pump I assume? Which is leaking the freshwater or sea water pump? If you've got coolant leaking from a pump then that would be freshwater/coolant pump not the raw water (sea water) pump. ???

[Snoz]

Sorry if I called it the wrong thing, I'm extremely new to this..

It circulates my water/coolant, it is called the sea water pump on the Penta MD17D exploded drawing I have here. Its mounted at the rear of the engine above the reverse gearbox. I have a separate sea water pump for the exhaust cooling.

The reason I am exploring this option is mainly because of cost and also future ease of replacement, I have been quoted just under $700 for a replacement pump.
I thought if I could get the right pressure/flow details and I thought that a flexible impeller might not be suitable for the temperature.

Thanks for your reply,

Andrew.

Originally Posted by belizesailor

Theoretically I suppose, but why? What are you looking to improve upon? You are not likely to find any specs for an electric pump for this use because this would not be a typical instalation.

Also, you state that coolant flows thru the sea water pump....you mean fresh water pump I assume? Which is leaking the freshwater or sea water pump? If you've got coolant leaking from a pump then that would be freshwater/coolant pump not the raw water (sea water) pump. ???

[jimbunyard]

Typically you would just rebuild the existing pump, complete kits can be had for less than 100.00 usd. Don't know where you're located, but if you need a new pump (sometimes they can't be rebuilt) the Volvo P/N I found is 829825. There is a new one on ebay at this moment for 349.00, There is a new one at 877-621-2628 for 375.00, or you can try Depco in Florida at 800-446-1656 (these guys have good prices on repair parts, knowledgeable and helpful too).

These pumps are usually made by an outside vendor for the engine manufacturer, Volvo typically uses Johnson pumps, so if you find the actual Johnson p/n (which may be stamped on the cover plate), you might be able to find it for less than 350.00....

At least one of the problems with using an electric pump is that the output is constant, with an engine driven pump as the rpm increases, the pump output also increases.

[belizesailor]

+1. I would go with a rebuild.

You will not find a drop in replacement elelectric pump because no one does this. Reeinginering to use electric (which I've never seen on a marine engine) will be more complicated than you think and will be a one off proprietary fix. Flow rates are critical and if you get it wrong you can severely damage the engine. Either too little or too much flow can create cooling issues.

The fresh water pump is essentially the same as an automotive sytle pump. Probably just needs new seals/bearings. The pump bodies last indefinately unless damaged. A good automotive machine shop can probably rebuild it for you for a relatively modest cost. Almost certainly cheaper than a good quality, high temp electric pump, which ain't cheap either.

Are you certain the pump itself is leaking?

[Snoz]

Thanks for all the replies, all have good information that I was unaware of and that's the reason I asked here.

The electric pump option was suggested by others, prior to posting my question I found a youtube videos showing the modification that they had done.

This leak is new, I always check the coolant level as a prestart before leaving the dock as I try to be very cautious with everything because I am so new to owning a boat. The leak point was not visible and I have had a good look at all the joins where I could get my head or hands into. I pressure tested my cooling system via the header tank using tap water (about 87 psi) and all the joins and hoses was solid but my mate noticed a leak in the bottom of the pump.

I now know from previous replies that the electric pump isn't the simple fix we thought it might be, I have ordered a kit for it and worst case I can purchase the new unti that jimbunyard told me about on ebay.

Thanks to all for your advice.

Regards,

Andrew.