Sherwood water pump & Rebuilding a Water Pump LINK

[Momentum M]

Thanks for the comments guys...and Stu just to reassure you that the belt was secured AFTER the pictures were taken.

[Tom Glennon]

my 87 M25XP has the old style sherwood pump, and although it was "rebuilt" a year ago, I still had weeping issues last season.
I would just as soon replace it... so what is the recommended replacement? The old has a 4-bolt attachment... from the pics of the newer one... doest appear it would be a direct swap out.

Would love to hear what others have done.

[Michael Shaner]

Well, at a minimum, there are at least two "old sherwood"s left on the planet...

On second thought, the existence of your sherwood may be devaluing mine... 

Tom, did you personally rebuild it? I just received all the components to refresh the little guy...restore it to it's former glory, if you will. I ordered everything but the cover, shaft and housing...hope it isn't a lost cause...

[Stu Jackson]

I would just as soon replace it... so what is the recommended replacement? The old has a 4-bolt attachment... from the pics of the newer one... doest appear it would be a direct swap out.

Tom, the Oberdorfer is a straight swap.   Oberdorfer Model 202 M-15

Also look up DEPCO on this board for a source.  many discussions on Oberdorfer, Depco and Sherwood.  The advantage is that the Oberdorfer is serviced easily from the front, although ken Juul has reported that he has no trouble with his Sherwood access.

Rarely do the bodies of the pumps go bad, but rather the seals and bushings which make it weep which is the warning to replace them.

Redoing the seals by a yard is almost as expensive as replacing the whole pump!  If you learn to DIY, it's a no brainer: keep the pump and repair the guts.

[Tom Glennon]

Thanks Stu.

I did have all the components but not a press for the "cup seals" so had a yard do it.

They were expensive, and in hind sight, I should have done it myself!

[Stu Jackson]

...and in hind sight, I should have done it myself!

Tom,

Me, too!    Calder has a good description of how to do it.  He used deep well sockets.

Maine Sail also provided a good visual description of this on co.com, "Rebuilding a Water Pump" here:  http://forums.catalina.sailboatowners.com/showthread.php?t=106156

[Michael Shaner]

very informative guys (and MS)...thankx!

[Ken Juul]

normally the hardest to replace part is the shaft.  If your shaft is still in good shape, the rebuild should be straight forward.  Mine was shot, visable wear just using straight edge.  Bought a new one, old one finally went in the trash after sitting on the corner of the work bench for about a year.  Couldn't figure out any McGiver uses for it

[Fou Du Large]

I have the same on my M-25
This is a Sherwood pump.

The impeller kit Sherwood 10077K is what you need but i tell it by memory.
'm actualy in Florida but come back in Quebec Ca. next week.
I will verify the kit no. as soon as possible. BUT I'M PRETT SHURE i gave you the wright no.

[Fou Du Large]

Be very carefull when you remove the impeller...
D'ONT PULL the shaft...  Otherwise you will must remove the pump completely to replace the pin (inside) coupling.

There is a little snap ring to retain the impeller.
You remove this snap-ring and push with a screwdriver on the end of the swaft and pull the impeller with pliers.

Excuse my english........

[Stu Jackson]

Be very carefull when you remove the impeller...D'ONT PULL the shaft...  Otherwise you will must remove the pump completely to replace the pin (inside) coupling.

This has been an "urban myth" with some limited justification for many years.  The very, very, very early engines?/pumps? reportedly had a shaft with an indent in it.  If so, this "don't pull it" concept is true.  Ya just don't know until ya pull it.

However, all the rest of the time, over 99% or more, the newer pumps had a male shaped type fitting at the end of the pump shaft, and there is no reason it cannot be removed and replaced without pump removal.  It fits right back into the engine, 100% of the time.

How do you know?  You worry like I did and the first time when trying to take the ring off the impeller while the shaft is still in the pump in the engine, the shaft slipped out of the pump and engine!  I didn't have a choice.

If your PO left you a spare shaft you could look, too.

The Oberdorfer pump shows part #7 with the slight protrusion (male end) towards the pump.  See: http://www.marinedieseldirect.com/catalogs/catalog_group.php?owner=mdd&page_ident=200142-57&model=M-25%20/%20M-25XP%20/%20M-25XPA&manufacturer=Universal&title=Orberdorfer%20Water%20Pump&quant_position=&catalog=200142&printparts=200142&printservice=200151&printoperators=200157&comment1=

I remove the shaft all the time when doing maintenance to check the shaft and replace the impeller.

If you have a specific engine serial number (or boat # - which must be very, very low) where this occurred, please let us know, because it's not the pumps or else different pumps and different pump manufacturers all wouldn't work in our similar engines.

Let's hear from you.

[Michael Shaner]

Ya just don't know until ya pull it...

Well, I pulled it...and it was a totally harmless experience. "Ye Old Sherwood" has been restored to all of it's former prowess. Just a small contribution of 76 bones preserved a bit of maritime history...truly a selfless act. 

ps. If it gives up on me in short order, donations for one of those shiny new Sherwoods will be graciously accepted! 

[Ron Hill]

Guys : I just installed a new M25XPB with a new model Sherwood #G908 raw water pump.  I really pumps more water than the Oberdoffer!!

BTW, I also routed the raw water inlet hose so the drive belt in NOT captive by any water hoses and can be easily changed.  Same set up could be for the M35B engine. 
Watch the Mainsheet for a Tech Note article and pictures - coming soon!!     

[Michael Shaner]

Ron...you put this M25XPB in Apache??

[Ron Hill]

Michael : Sure did!! 
I'm still in the engine break-in mode, but IMPRESSED with the way it moves the boat thru the water.