Water Pump (fresh water)

[sailorboy1]

My recent v-belt issue has got me thinking, how long are people getting on their engine primary water pumps?

[a64pilot]

It’s likely that one thing that I’m not carrying a spare one of, and am almost certain mine is 30 yrs old.
I guess I should, but failure ought to be slow, beginning with a leaking seal that slowly begins to leak worse and worse
They seem identical to an automotive pump, and if so cleanliness of the coolant and using a coolant that is silicate free, ought to have the pump last a good long time, as in thousands of hours and decades.
Silicates if I get the term correct can or will eat up the seal.

[Sailmonkey]

We got 1600 hours on ours. But I’m pretty sure that our belts being too narrow and squealing when the alternator loaded up, that led me to excessive belt tension, led to the early demise of the pump.

[sailorboy1]

It's the belt thing that has me questioning the water pump life. since it appears belts don't last as long on boats why would you expect the water pump to (1600 hours is way less than the engines on the 2 boats I've owned)?

I looked into just quicky the other day and it looks I can get an aftermarket pump for around $130. Bet if I get one I guarantee that I will NEVER need it.

[sailorboy1]

surprised so few people have had to replace their water pump

[sailormed]

Had to replace mine last month, leaking seal. Yanmar 3JH4E, 1200 hours.

[a64pilot]

Originally Posted by sailorboy1

I looked into just quicky the other day and it looks I can get an aftermarket pump for around $130. Bet if I get one I guarantee that I will NEVER need it.

For that kind of money, I’d carry one, I have a spare aftermarket starter in stores. I used to say that about keeping a spare, but I have had to use my fresh water electric pump spare, and just about two hours ago pulled my Watermaker boost pump spare out of spares and installed it.
What is your source?
I think your right about the belt thing, with the super high tension people are running to keep belts from slipping, that has to be a factor on water pump bearing wear, and possibly the crankshaft front bearing as well.
It seems at least on automobiles that the bearing wears in the waterpump, that allows the shaft to wobble, that wears the seal and you get a leak, usually it’s a very slow leak and will leak slowly for hundreds or thousands of miles. What usually keys me in is the smell of pancake syrup when I park the car, I swear hot antifreeze to me smells just like syrup.

[RainDog]

Ours went on our last cruise. It went pretty fast. Seemed fine one day and was badly leaking the next. Yanmar HM35F. I am not sure how many hours were on it, but I would bet <1500.

[sailorchic34]

I have over 2,000 hours on my fresh water pump. I suspect mine will last at least another thousand hours. I believe the key is using the standard alternator and not over tightening the belt. Side loading is probably the number one killer.

Why? Because a larger alternator requires more belt tension and that puts more sideloading on the water pump.

My raw water pump on the other hand has been completely rebuilt. But that sees salt water and sediment and that is lots rougher on the seals.