raw water pump replacement

[capnbgm]

I am going to replace a leaking Sherwood raw water pump with an Oberdorfer pump.  As I talk to different distributors, I cannot find agreement about the Oberdorfer pump I need to buy.  Can anyone help me with this?  Does anyone know the part number, or some way to identify the right Oberdorfer pump?  Thanks.
Cpnbgm

[wes]

Do you have the Universal M12 diesel? That's what I have on my 1988 CP 27. I ordered the Oberdorfer pump from Catalina Direct, their part number Z2857. The pump is actually an Oberdorfer N202M-15, so you may be able to source it cheaper elsewhere. It has 3/8" FIP threads so you will need fittings to match your hose diameter.

https://d1pkofokfruj4.cloudfront.net/media/upload/resource/p/Oberdorfer-N202M-Datasheet.pdf

Wes

[capnbgm]

I have an 88 also, and I thought I had the M-12.  But the pump on the link you sent (thank you) bolts to the block.  Others that I have seen have a square mounting flange that bolts on.  My Sherwood has a circular mounting flange and mounts to the block with two l-shaped brackets.  It has no bolt holes in it.  I have found another pump that has the round mounting flange without the bolt holes, but suppliers tell me it is not the right replacement for the M-12.  What do you think? 

cpnbgm 

[wes]

Crawl down your port side cockpit lazarette and look for the serial number nameplate on top of the engine. It will confirm that you have an M-12 which is nearly certain on a 1988 boat.



Regardless of the bracketry on your Sherwood pump, if there are two threaded holes on the engine block adjacent to the water pump drive shaft hole, the Oberdorfer should fit. It's true that the Oberdorfer mounting bracket looks different than the Sherwood, but all that matters is that the holes line up. Here's what my old Sherwood looked like (yours may be different - there were multiple different water pumps installed by Universal during the years the M12 was produced). Note only 2 of the holes on the Sherwood mounting plate were used.







Wes

[Allure2sail]

Hi:
Switched myself, better designed pump. I take the impellor out every winter. That way they last a real long time. On my sixth year !!!
Bruce

[capnbgm]

Thank you all!

[Allure2sail]

Hi:
Look in the consignment shops, pull, the front cover off to check the bushings are good and that the shaft itself is not worn out. Shafts are expensive and replacing the impeller is a given anyways. Good luck and don't bother with the impellers that say you can run them dry, they are junk.
Bruce
S/V Allure