Lifespan of a fresh water pump

[Frank Langer]

Hi,
Does any one know the approximate life span in years, engine hours or other measure, of the fresh water pump (not the raw water pump) on our Ericson/Kubota diesel engines? And what causes them to fail? Early warning signs?
Thanks,
Frank

 

[Loren Beach]

Our former Universal M25XP (Kubota based) diesel had the same fresh/coolant pump all its life - over 2000 hrs. It was an iron-vane impeller, and while some folks have commented about seal leaks, I never had one happen. That pump was fine when I replaced the original Universal (Kubota) diesel in 2018. Are you seeing any leaks at present?

 

[Frank Langer]

Thanks for your reply, Loren.
I replaced my fresh water pump in 2018 after the old, perhaps original, one began to run rough and looked rusty inside when I removed it.
This one is now running well, no leaks or squeals, but it's 7 years old, 1200 engine hours.
I'm planning a sailing trip this summer with my wife to more remote areas, and am thinking preventive maintenance. I've had to return twice previously from such trips due to problems arising (over 16 years of these cruises), and am trying to avoid that if possible. I'm meticulous about maintenance, but it's hard to know the life span of things like a fresh water pump. Yet it's critical to engine operation-- hence my question.
Frank

 

[gabriel]

coolant coming out of the pumps weep hole is an early indicator of pump failure.

You can extend pump life by changing your coolant at the prescribed interval, the corrosion inhibitors in it get ‘used up’ over time and can lead to a rusty pump.

 

[JSM]

The freshwater pump on our 87 34-2 / Universal M25xp made it to 2021. There were no warning signs that it was on the way out. We were motoring into our mooring when it began to squeal loudly as it had seized and the belt was sliding around the pulley.
A new pump from the Universal distributor was $350. I was able to source one at a local Kubota dealer for under $50.

https://www.amazon.com/New-Kubota-D950-WATER-PUMP/dp/B00DV2VBLQ

 

[Prairie Schooner]

coolant coming out of the pumps weep hole is an early indicator of pump failure.

You can extend pump life by changing your coolant at the prescribed interval, the corrosion inhibitors in it get ‘used up’ over time and can lead to a rusty pump.

Gabriel,
Is this the weep hole you speak of? I was just cleaning this up for painting, saw the hole and was wondering about it. What is it's function besides as a warning system for wear?

 

[gabriel]

Wasn’t sure if your question actually, but I found this explanation:

makes sense to me.

 

[Prairie Schooner]

Wasn’t sure if your question actually, but I found this explanation:

makes sense to me.

Perfect.
It never occurred to me there would be a video on a topic so specific.
Thanks!

 

[Kenneth K]

Wasn’t sure if your question actually, but I found this explanation.

Yeah, that's awesome! I had an old Ford pickup where the belt would regularly start to squeal if the truck was parked facing downhill. After years of this, I sort of figured the squeal was from coolant leakage onto the belt, though it never developed into water pump failure. Probably just weep hole leakage just happening to land on the belt.

 

[Kenneth K]

Hi,
Does any one know the approximate life span in years, engine hours or other measure, of the fresh water pump (not the raw water pump) on our Ericson/Kubota diesel engines? And what causes them to fail? Early warning signs?

I think seals and bearings are the failure points. Bad seals cause leaks and bad bearings cause noise. There's really not much else inside the pump that can go wrong.

For comparison, on my 1995 BMW, I've had two water pumps replaced over the 28 years I've owned it. If you're worried, you can always carry a spare pump and gasket. And, contrary to the opinions of some, our simple, low-tech tractor diesels don't require any special type of coolant. Just don't mix coolant colors/types within your engine.

 

[ConchyDug]

I found mine near failure like 4 years ago. The bearings were rough when I side loaded the pulley by hand. It still spun but I could feel the bearings had a "grit" feel to them. When I removed the pump to replace it I could see radial play in the bearing. If I remember right, I was changing belts out because I found cracking on the old belt and discovered it. As JSM pointed out just buy an extra one and keep it on the boat with some RTV.

I had a 2012 Grand Cherokee that blew up a pump within 8yrs... so I dunno it's like these things are machines and they wear out eventually.

 

[Pete the Cat]

I carry a spare pump for my engines. Most small diesels use generic standard automotive fresh water pumps on the tractor blocks--so they are available after market on EBay or Amazon with a little research. The one from my 25XP cost $50. Nasty if one starts to leak on a trip. But I also carry a spare raw pump. You can tell I have had some bad experiences. I have had to change them more than once when underway in my 50 years of cruising. Cheap insurance in my book.