Older M25 sherwwod pump seal replacement

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Keith's picture
Keith
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Older M25 sherwwod pump seal replacement

I have the older type Sherwood raw water pump on my M25 engine and in the process of replacing the seals.
Questions I have are:
What is the correct installation direction of the two seals?
How is the inner seal removed without damaging the carbon bushing?

Also I checked the Sherwood web page for a schematic drawing for this pump but could not find, as I did not have the model number, could some one help?

Keith & Donna
SV: Victoria Dos
Hull #431
Sea of Cortez, Mexico

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stu jackson c34
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Stu Jackson, C34IA Secretary, C34 #224, 1986, SR/FK, M25 engine, Rocna 10 (22#)

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Keith
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I found the schematic for the pump on the Sherwood web site. I would like assistance with removing seals without damaging carbon bushing.
[ATTACH]743[/ATTACH]

Keith & Donna
SV: Victoria Dos
Hull #431
Sea of Cortez, Mexico

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PDF icon Sherwood raw water pump MPG_M5.pdf181.22 KB
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plaineolde
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My tool of choice is a slide hammer type seal puller like this -
[url]http://www.google.com/products/catalog?q=seal+puller&oe=utf-8&rls=org.mo...(link is external)

This one is cheaper, but would probably work too.
[url]http://www.google.com/products/catalog?q=seal+puller&oe=utf-8&rls=org.mo...(link is external)

With either, you basically slip the 'hook' through the seal, catch the edge, then tap it out, moving the hook around so the edge of the seal is pulled out evenly.

That's without seeing the actual part, but when I rebuilt my Oberdorfer pump, that's the technique I used.

Gary and Cathy Price
1997 C36 Mk II Tall Rig/Wing Keel Imagine...
Hull # 1617
Worton Creek, Md.
Northern Chesapeake Bay

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Ken Juul
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Once you slide the shaft out of the pump it should be fairly easy to remove the seals. Carefully slip a long screw driver or similiar through the carbon bushing until it rests on the outer seal. Tap out with a hammer. You may be able to do the same with the inner seal, if not, from the engine end insert a hooked piece of wire and pull. As you can see in the diagram the seals point in opposite directions. Engine side the lips of the seal point at the engine to keep the oil in, sea water side the lips point at the impeller to keep the water out of the engine.

Ken and Vicki Juul
SV Luna Loca
C34 #1090
Chesapeake Bay

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Peter Taylor
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Posts: 107

Keith
Here is a fantastic article from a C 28 owner who describes the procedure to replace the water pump seals.

It has some good hints and great photos.

If I knew how I would post it in the maintemnance section.
Having read this I am quite confident to renew mine which has a very slight leak. It seems much more sensible than replacing the whole pump or installing an Oberdorfer. I might do the latter eventually.

[url]http://catalina28.blogspot.com/2011/07/seat-and-seal-assembly-replacemen...(link is external)

Peter Taylor Melbourne Australia. Altair  #2227 2005 C36 Mk11

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LCBrandt
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Posts: 1282

Peter, rather than post an article on the C-28, why not document the fix on your C-36? Just remember to take lots of photos (so easy to do with today's digital cameras), and then write a simple step by step as you go. If needed, we can help you wordsmith the article. Need help? Just ask.

Larry Brandt
S/V High Flight #2109
Pacific Northwest, PDX-based
2002 C-36 mkII SR/FK M35B
 

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Keith
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Posts: 25

I was not able to remove the internal seal without damaging the carbon bushing. It has been suggested to me by another boater that I should take the pump hosing and shaft to a local machine shop here in Mexico and have a new bushing machined out of brass. Has anyone replaced the carbon bushing in there Sherwood water pump with a brass bushing? Any comments would be appreciated.

Keith & Donna
SV: Victoria Dos
Hull #431
Sea of Cortez, Mexico

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