Sea Water Pump symptom and question

Maine Sail · Dec 5, 2009

Stephen K said:
I researched the archives here, the C34 web site and Torrensen Marine...a lot of good information was found. I understand how the pump pulls in sea water and circulates it to cool the closed loop system. I don't understand the "insides" of the pump (how the seals keep the water and oil sides seperated), so here's my symptom and question. I have the new model Sherwood pump on my Universal 25XP.

The oil level on my dipstick seems to have gone up and is past the full mark (a little). My oil looks black and does not appear to have a milky cast. I also noticed a drop of oil from the weep hole of my sea water pump. I do not see a lot of old oil drops from around the weep hole.

Are the two related? Is this something to be concerned with? Should I just continue to monitor or replace the pump now?

While not the same pump the general principles are similar. It should give you an idea of how they work and go together..

Re-Building A Raw Water Pump (LINK)

Stu Jackson · Dec 5, 2009

Here's a recent C34 MB discussion about Sherwood pumps: http://c34.org/bbs/index.php/topic,5338.0.html

Please also read the embedded links in that topic.

This is related: http://c34.org/bbs/index.php/topic,5328.0.html

Maine Sail · Dec 5, 2009

Stephen K said:
Hi Maine Sail,

Thanks for your link. I actually read it awhile back and just reviewed it again...(and need to a couple more times).

I still have the same questions and to my limited understanding, I don't think that the slight oil drop form the weep hole is linked to my oil level rising....what do you think?

Maybe the oil has accunulated some moisture that I just need to just burn off by running the engine to temp. a couple of hours?

A couple of thoughts.

1- Too much oil could cause the oil pressure to rise and thus force oil out of a marginal seal.

2- When you filled the motor with oil & checked it, maybe you did not allow for sufficient drain back time and thus added more than you should have?

3- If it's not milky gray, and you have more than you should, when you had not, it could be a fuel issue with fuel getting into the oil..

4- If it was from condensation, and it was that overfilled, it should have a milky gray consistency..

If I were to guess I might opt for the opinion that you simply over filled it? Change it, get it to the correct level, and with enough wait time for full drain back into the pan. Run it for a while and see of it goes up again. If it does and is not milky then the most likely scenario is fuel contamination. Water contamination is rather easy to spot..

Stu Jackson · Dec 5, 2009

Stephen K said:
...I don't think that the slight oil drop form the weep hole is linked to my oil level rising....what do you think?

I agree with MS's suggestions. You also shouldn't neglect the issue with your pump. don't get so fixated on the oil level that you neglect the pump weeping - it's telling you something pretty important.

I once overfilled my oil. MS is correct on the possible reasons in your case. Instead of replacing it all, I just took a little bit out so it hit the dipstick mark properly.

Fix your pump.

Bob S · Dec 7, 2009

Stephen,

I'm soon to be rebuilding mine. I have oil leaking from the weep hole. I think the Sherwood is cast iron not bronze like Mainesail's. I have yet to remove her from the engine but plan on doing it over this winter. The rebuild kit was twice what Maine's cost. I read the C34 topic Stu references. Some really good posts on the subject. Mine will be done before she is launched the coming spring.

Bob S · Dec 8, 2009

I was online last week trying to find the rebuild kit which I thought I found @ Torresen Marine for 275.00. I wish I bookmarked it. Checking today all I can find is the new Westerbeke replacement which is the complete pump for 394.24 ouch!

http://shop.torresen.com/marine_diesel_direct/Universal/index.php?p=details&mfc=Universal&sku=302648

I'm going to do some more research and if I find anything I will post it here. Seems like the Sherwood pump # 302648 used on my boat is obsolete.

Stu Jackson · Dec 8, 2009

Sea Water Pump & Browser History

Bob, if you didn't bookmark it, then try your HISTORY on your browser. If you were there, it should have kept it unless you clear your history all the time.

If the Sherwood bugs you for any reason, go back to my link and buy an Oberdorfer. Yes, some stud mods are required, but the pump parts can be purchased for less at Depco.

Bob S · Dec 9, 2009

I was told by a salesman at Depco Pump that Sherwood has obsoleted the G903 / G908 universal part #'s 302648 & 302837. It was replaced by Westerbeke # 42175. This was a deal between Sherwood and Westerbeke to exclusively make this pump for them. For a while there will be some parts available but they are no longer making the shaft which is the most important part. Sometime over the winter I will remove mine and take it apart to see what kind of shape it's in. Stephen, let me knowif you find anything different.

Thanks
Bob

Glenn17467 · Dec 16, 2009

I replace my Sherwood G908 2 years ago. Purchased the pump only from MarineParts.com for $275 + shipping. If you also want to replace the brass retaining blocks you have to buy the complete assenbly from Torresen at $400. I reused th blocks and replaced all bolts with stainless. Be sure to check all hoses from the pump to the muffler. Mine was 95% clogged at the HX inlet and since the weep holes were rusted over sea water went through the seals and into the engine. I caught it quickly and did not give the water time to turn the oil milky but the oil level rose dramatically. Does not sound like your case but check the hoses.