Sherwood M71 Pump rebuild

[James Buntyn]

I have a Cummins 4BT with a Sherwood M71 seawater pump.  The boat is a 2009, and I’ve had it for 2 years, but I have no idea how old the pump is.   I’ve replace the impeller but the pump leaks slightly. 

According to the Sherwood G Series Technical Guide, you must remove everything from the gear side just to remove the seal.  This will require a hydraulic press and skills I don’t have.  Just to replace a seal..

 

Other than buying a replacement pump, any ideas on how to fix the seal without a machine shop?

Thanks

Topic

[James Buntyn]

Thanks Tony.   I appreciate all the feedback received through this forum. A great resource! 

[Tony Athens]

IMO, no better replacement

[James Buntyn]

Thanks Tony.  And any alternatives for this pump, different (better) brands or models?

[Tony Athens]

Yes-100%  Sherwood M-71 pump

[James Buntyn]

Dan, from the photos, can you tell if this is the M71?<br /><br />

Thanks

 

Tony

[James Buntyn]

Tony, I agree with your humble opinion.   👌  This is the first time I’ve tried to do more than change the impeller.  Very disappointed in the design.  Do you know if there is another brand or model that is a better design?  Appreciate your time!

 

Tony

[Tony Athens]

IMO, Unless your have the right tools, don’t try and rebuild and are skilled in this type of work.

[James Buntyn]

Thanks Dan.   ESN is 60131064.   Photos are attached.

[Dan]

Sherwood pump

Sure its a M71 (4BT)  or a G1503 (4BTA) ? Post a pic or supply the ESN for clarification.

If its the M71 these are cheap and easily available or Depco pump in Florida will recondition it.

<i>“This will require a hydraulic press and skills I don’t have”</i>

If you don’t have a press or the skills your’e in over your head

<i>“Just to replace a seal”</i>

Good chance the shaft is the real issue + seat and seal/the body or the backing plate are probably worn.

If its the G1503

Your’e in way, way over your head, the G1503 is a self destructing time bomb that has been known to fail (and destroy the engine) at very low hours.

<i>“leaks slightly”</i>

Leaking salt water onto an already over stressed bearing (poor design)

<i>“This will require a hydraulic press and skills I don’t have”</i>

as above

<i>“Just to replace a seal”</i>

as above

Either way, be careful going forward the Sherwoods have a known history of failure and dumping the gear into the timing cover and destroying the engine.

 

[Author]

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