[C320-list] Johnson Water pump replacement for Yanmar

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Dean Agee

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Apr 24, 2022, 11:10:10 PM4/24/22
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My Johnson F4B-903 pump froze up. I disassembled it and found the smaller bearing had failed.

It appears there are number of replacement options. Does anyone have a recommendation for a pump? For a vendor?

Thanks!


Dean Agee
AhSeaHola, #912

Bay St Louis, MS

Dennis Cookson

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Apr 25, 2022, 3:50:55 AM4/25/22
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Dean, I had a similar situation and chose to refurbish the pump. Replacement bearings and o-rings are of standard size and readily available. Any marine engineer could fit these for you.

Dennis Cookson
Catalina 577

> On 25 Apr 2022, at 04:10, Dean Agee <da...@iserv.net> wrote:
>
> My Johnson F4B-903 pump froze up. I disassembled it and found the smaller bearing had failed.

RONALD HODEL

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Apr 25, 2022, 9:03:38 AM4/25/22
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I bought a new Johnson F4B-903 pump and had the one that was failing rebuilt. I put the rebuilt one back on the boat and I carry the new one in my engine spares box. It was the more expensive option but we were off cruising and going places where there would have been no place to have a failing pump fixed. (Expensive option / cheap insurance).

Ron Hodel
#1070 Lokomaikai

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> On Apr 25, 2022, at 12:51 AM, Dennis Cookson <den...@cooksons.net> wrote:
>
> Dean, I had a similar situation and chose to refurbish the pump. Replacement bearings and o-rings are of standard size and readily available. Any marine engineer could fit these for you.

Joe Grande

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Apr 25, 2022, 4:39:09 PM4/25/22
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While I have replaced both
engine water pumps on Whisper #772 over these 18 years, I ALWAYS carry at least one extra impeller for the raw water pump.
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From: C320-list <c320-lis...@lists.catalina320.com> on behalf of RONALD HODEL <ronan...@me.com>
Sent: Monday, April 25, 2022 7:03:28 AM
To: C320...@catalina320.com <C320...@catalina320.com>
Subject: Re: [C320-list] Johnson Water pump replacement for Yanmar

Jeff Smith

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Apr 26, 2022, 10:09:43 PM4/26/22
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I just to rebuild my pump (Perkins not Yanmar). Given that your bearings
failed, just realize that is a more difficult task than simply replacing
the o-ring seals. I used a ball joint press kit from an auto parts store to
press the bearings, but it was far from a smooth operation. My thought
process was that, for $35 - $45, it was worth an attempt before I committed
to $250+ for a refurbished pump.

YMMV,
Jeff
‘94, #121

Joe Luciano

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Apr 26, 2022, 10:55:58 PM4/26/22
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One thing I try to do which I believe extends the life of raw water pump bearings and seals is flush the raw water pump with fresh water any time the boat is likely to sit for more than a week. I have a connection between the thru hull valve and the strainer that I can hook up a clear hose to and let the engine pull from a 5 gallon bucket of fresh water. I’ve only had to replace pump seals once in 15 years. And the one time was early on before I installed the fresh water flush…..

Joe Luciano
#1044

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> On Apr 26, 2022, at 7:09 PM, Jeff Smith <svsailm...@gmail.com> wrote:
>
> I just to rebuild my pump (Perkins not Yanmar). Given that your bearings
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