The Sherwood Pump - Redux

[Stewartn]

I am sad to report that almost 2 years to the day, after replacement with a brand new pump from Hansen, the "new" Sherwood pump is leaking. In 2009 the weep holes were corroded closed and we never saw the leak. We lost the season with haul out, engine removal, etc. because of sea water in the engine. Well I see the leak this time. Ordered a new pump at $360. Spoke to Hansen - Lot's of excuses. Question is; this pump has to be rebuilt or replaced every 2 years? Pump has about 125 hrs on it. Everything else is working fine. Temp gauge is steady as rock, right below 170. Exhaust water would fill a battle ship. Riser, Heat Xch, Nipple all checked and were fine 125 hrs ago when the engine was removed.  You'd think
Mr. Westerbeke would figure out how to marinize a tractor engine with a better pump. Certainly lessens my level of comfort with Universal. Comments?

[Stu Jackson]

Stewart,

Hi, again. You are pretty much a "regular" here on the message board.

So, I'm sure you already know that if you do a simple search on "Sherwood pump" you could be reading for YEARS!  

Many folks have replaced those buggers with Oberdorfer pumps, less expensive, etc.  It's been written up and discussed so many times...  There's even a wiki article about doing it on newer engines.  http://www.c34.org/wiki/index.php?title=Replacing_a_Sherwood_Water_Pump_with_an_Oberdorfer

Many, many folks have these Sherwood pumps and can live with them.  If you can't, won't or choose not to do so, there ARE answers out there...

Your boat, your choice.  

[Ron Hill]

Stewart : The only excuse that I've gotten from Westerbeke as to why they selected a Sherwood pump for the 35 hp engine - is that it pumps more water and the M35BC engine needs that additional water for cooling.  (You even have a longer HX than the M25XP engine)

You can call DEPCO (800)445-1656 and tell Joe that you need parts 10,11,12 in your parts manual for a G908 Sherwood pump.  They come together and you can rebuild your old pump.  As I recall they cost about $20/25.  A lot less that the price of a new pump.  

Some people have changed to an Oberdoffer, but I and Westerbeke wouldn't recommend it.

BTW, to change out the lip seals in an Oberdoffer is not exactly a piece of cake either! 
Hope this helps.  

[Stu Jackson]

I agree, rebuilds are the way to go, since the pump itself rarely gets worn.  It's ONLY the seals that go, and Ron did a great description of those seals in one of the earlier Sherwood discussions.

We've also written ad nauseum about how most of us, me included, buy new pumps 'cuz if we don't want to or physically don't think we can change the seals ourselves, we pay someone to do it for us and it costs as much as new pump!  Regardless of model.

I simply and personally disagree about the water amounts "issue" of the Oberdorfer pumps, regardless of what Joe told Ron, simply because of the wiki article, if nothing else.  OK, they may pump a tad less, but they work.  They do work.

The "Oberdorfer pumps less water than the Sherwood" crowd has been around a looooong time, but I place little credence in it because Oberdorfer pumps DO bloody well work even on M35s.  Just read the wiki.

And Ron has also told us many times that Sherwoods aren't discounted and cost a lot, lot more of your hard earned $$.

If it was my boat, there wouldn't even be a choice.

Oh, wait, I already HAVE an Oberdorfer.    

Hey, Stewart, you did say "Comments?"    

[Ron Hill]

The Joe that I am getting my information from was not at DEPCO, but Joe Joyce Westerbeke Service Manage.  Having experience with both pumps I can definitely say that the Sherwood pumps more water. If your engine is still under warrentee, I "sure as hell" wouldn't change to an Oberdoffer!!

Having had Oberdoffer pumps for over 20+ years I can assure you that the stainless shaft wears and does get scored, the carbon bushing and the face plate also wear.  The shaft wears more than you think because water is not the best lubricant.  That's why it goes first. 
You have to replace both lipseals at the same time, because to replace the water seal you have to remove/destroy the oil seal first.  You or your mechanic must be very careful when removing those lip  seals NOT to score the inside wall of the pump.

As Stu says YB/YC      OUT

[Roc]

Call Sherwood and tell them your situation, that the pump is leaking after relatively low use.  They might send you a new pump.  I had a pump go out after less than 20-30 hours (can't remember exactly), and I told them that was totally unacceptable and they sent me a new one, after I sent them the one that leaked and they decided to replace it. It's worth a try.

[Tom Glennon]

I replaced the sherwood on my M25XP with an Oberdorfer... Now I have one brand new Sherwood impeller, and one lightly used, along with gaskets if anyone is interested in buying these, please let me know.

Tom

[John Langford]

Just motored 4 hours straight at 2200rpm on a completely windless and hot day and the Oberdorfer pump on my M35BC performed flawlessly. The temp gauge stayed rock solid on 160 degrees the whole time. The bronze body, lower cost and wide availability make the Oberdorfer an attractive alternative to the Sherwood pump that rusts, leaks way before it should, and is sold only by Westerbeke at an extortionist price. The required modification of the Oberdorfer is easy to do thanks to Nile Schneider's wonderful illustrations. It's a no brainer.

[Ron Hill]

John : I'm glad that you are happy with your successful modification and not overheating.  Good luck