Shurflo water pumps low flow

[sailingharry]

Our boat came with two water pumps, both by Shurflo.


Fresh water -- 4148-153-E75 10A 4.0 GPM
Washdown -- 2088-534-944?


Both pumps work "fine" -- the come on, they prime, they shut off on high pressure, etc. But both seem to be rather lackluster on flow rates.


I've heard anecdotal stories that periodic rebuilds provides great improvements in flow from these pumps. And Shurflo sells a wide assortment of pump components, including a complete new head unit -- lending credibility to the idea that they have a life expectancy.


My question -- what parts fail? I hate to just buy a new head unit and bolt it on, but at the price it's not a terribly expensive approach and leaves the old as a functioning spare. But, there appear to be 3 or 4 "layers" in the head, and I suspect that only one (or perhaps two) actually wear out.


Any guidance?

Harry
Circe
Saga 43
Mill Creek, Annapolis

[Stu Jackson]

There are two parts: flow and pressure.


Have you checked and cleaned the screens on your faucets?


BTW, that Shurflo is most likely the same one I've had on my boat since I bought it in 1998, and could well be OEM. It's just fine. Unless you're trying to run both the head and galley faucets at the same time.


Good luck.

[sailingharry]

Stu,

Thanks. Some more info:
* The galley is a brand new Home Depot kitchen sink faucet, so I don't expect any issues.
* The head is a straight tube out of the valves. Factory original (1998), but hard to see an issue.
* The fresh water pump is a 55PSI 4GPM pump. I get anemic pressure, and since modern faucets are designed for around 2 GPM flow rate, I would expect the pump to be well up to the task. I should do a timed flow test.
* I know, anemic flow is a good thing for the tanks. But I'd rather manage my water myself, than have a failing water system do it for me! Assuming it is failing....
* The washdown pump goes to a garden hose and sprayer. Wide open, it should be hitting pump capacity of 3.5 GPM (it's called the "Blaster" for Pete's sake!), and when my wife pulls up the anchor (ever since we got a new boat with a windlass, I don't get to do anchor duty....) I go up with a bucket to supplement the anemic sprayer. Again, I should measure flow rate.

Harry

[The Resailman]

Since it's both of them, I gotta wonder if they share a ground? If so, you might be onto something. If it were one or the other, then I might attack it different. Since it's both, I'd wonder about the commonality of them.

[Scubaseas]

Originally Posted by sailingharry

Our boat came with two water pumps, both by Shurflo.


Fresh water -- 4148-153-E75 10A 4.0 GPM
Washdown -- 2088-534-944?


Both pumps work "fine" -- the come on, they prime, they shut off on high pressure, etc. But both seem to be rather lackluster on flow rates.


I've heard anecdotal stories that periodic rebuilds provides great improvements in flow from these pumps. And Shurflo sells a wide assortment of pump components, including a complete new head unit -- lending credibility to the idea that they have a life expectancy.


My question -- what parts fail? I hate to just buy a new head unit and bolt it on, but at the price it's not a terribly expensive approach and leaves the old as a functioning spare. But, there appear to be 3 or 4 "layers" in the head, and I suspect that only one (or perhaps two) actually wear out.


Any guidance?

Harry
Circe
Saga 43
Mill Creek, Annapolis

I have in the past had issues with both #2 and #3 on my Shurflows. But more often #3 the drive assembly. Might just be "gunk" stuck under the valves though.

https://www.pumpagents.com/partpages...8-153-E75.html

I keep a spare pump onboard and then fix the broken one at my leisure. I use same pump for washdown as domestic water. When it breaks just swap it out then order parts as needed.

[SV__Grace]

Do you have an accumulator tank?

If not, this might be what you need to get the pressure for your fresh water system.

You might have one and not know what it is and it might be as simple as re-pressurizing it with an air pump, or it might need replacing as the internal bladders don't last forever.

For your wash down pump I have the same problem with a different manufacturer- Jabsco. Pump works great but the pressure is not great and it takes me 1/2 hour or so to wash the mud off my chain as I raise anchor.

I've been thinking about upgrading it but haven't looked into doing so and welcome suggestions!

[tomrealest]

I agree with all of the comments above. I have replaced the diaphragms in my Shurflo's on different boats. After checking everything posted above I would recommend calling Defender 800-628-8225 or by e-mail at www.defender.com/contact. They are very competent, helpful and reasonably priced

[Mike Banks]

I too have the pumps as you described. The washdown pump has had limited use, but the main pump was used for years. They have to be used with an in-line filter on the inlet side, or they can get bits of detritus in the pump itself.

The cheapest and easiest in-line filter is the one used by agricultural spray systems. It is all plastic and can be taken apart for cleaning.

The pump itself, or the motor windings or circuitry was not the problem on my pump, it was the rubbish bearings. The pump began to slow down and was noisy.

I replaced them after only a couple of years use with some stainless steel pre-packed Japanese bearings designed to do several thousands of hours.

Not only did the pump work better than when new, it also ran a lot more quietly. Why the manufacturers had not put in the good bearings at the outset--they only cost twenty or thirty bucks or so, beats me.

I still have the pumps today--they went on for another three years and were still working fine when I removed them.