Raw Water pump leak

[KWKloeber C-30 #3573]

is there any way to keep it out of the engine cooling circuit when I am motoring for several hours?

Well yes, sort of.  But your purpose?  To lower the water temperature? Stop a possible engine coolant leak at the WH?  Or shut off the potable water supply?

[KWKloeber C-30 #3573]

Do you have a check valve on the bilge pump discharge (not that I am suggesting one way or the other  )?

[waughoo]

Not sure on this, but I suspect your engine is heating up the water tank and blowing off the T&P valve into the bilge and that is what is causing most of your pump cycles.  That would explain why the bilge cycles for a while after you return to the slip.  The T&P is SUPPOSED to bleed off the extra pressure of the expanded water as it gets heated, so this is a normal situation, but perhaps it isn't sealing tight after it opens and it is weeping.  That is a typical failure pattern.  Also, if you use water from the hot water tap as the engine (or electric element) heats the water, the T&P won't have to blow it into the bilge.

[Ron Hill]

juna : The only way to "easily?" keep the hot water heater out of the engine cooling circuit is to take the input hose to the hot water heater and connect it to the output hot water heater hose! That cuts out the Hot Water heater out of that circuit.

A thought

[Stu Jackson]

I motored 1,650 nm from SF to British Columbia.  There is no reason to ever disconnect the water heater from the engine coolant system,  unless you have a leak in the hoses to the heater or a defective T&P valve.  The repair to the hoses I wrote up and is in Critical Upgrades.  The T&P replacement is easy - take it off and go to a hardware store.

[junaido]

I just returned from my trip. Engine behaved like a champ and got me through Deception Pass and Swinomish Channel etc. Temperature stayed at 160 almost all the time. Fortunately I was able to sail for at least half the trip. Now I need to give the engine some TLC. Number one item on the agenda is the water pump. I am not sure what kind this pump is, the label on the cover says something like "speedseal"?, a patent number, and not much else. Does anyone know what kind of pump this is, and what is the best way to fix it? Link to pic below.

pump pic

Thanks,
Junaid

[KWKloeber C-30 #3573]

@ junaido

Great that the trip was uneventful, cooling wise!

It appears to be an Oberdorfer but but can't confirm which model without more info.

Are you looking to replace it?  Service it?  Carry a spare?

To confirm,

+ please post a pic with the cover off (that is an aftermarket speedy cover)
+ what size are the inlet/outlet threads (thread on the hose elbows), 3/8" pipe thread or 1/2" pipe thread?
+ is your Heat Exchanger 2" or 3"?

[junaido]

I would prefer to repair it if possible. Pump with cover off

I have a 2" heat exchanger.
I think the inlet/outlet threads are 1/2".

[KWKloeber C-30 #3573]

I would prefer to repair it if possible. Pump with cover off

I have a 2" heat exchanger.
I think the inlet/outlet threads are 1/2".

Ok thx.  Does your aftermarket cover have an o-ring in it or does she use the paper gasket?

If you want to try salvaging it, the first thing is to inspect the shaft for scoring.  Just pull the impeller and shaft straight out and note the orientation of the tang on the end or the flat on the impeller end or mark a fin so you orient it correctly to put it back in.

It's an OLD pump and likely needs a new carbon bearing which isn't for most DIYs to replace.  You can have Depco or another authorized service center inspect and rebuild it.  Or simply try rebuilding w/o a new bearing and see what happens.

If she needs a new shaft the thing is with all the parts you're approaching the cost of a new pump with a warranty, which parts do not have.

So it depends on your ability and comfort level over trying to replace parts.  Lip seals are easy - the bearing is not.

Let's see what you find out about the shaft and take it from there.

[Stu Jackson]

Here's a helpful link for a pump rebuild for an Oberdorfer.  There is a Sherwood rebuild in the tech wiki but I'd opt to replace the Sherwood with an Oberdorfer because of all the dissimilar metals in a Sherwood.

Oberdorfer Pump Rebuild 101 - http://c34.org/bbs/index.php/topic,6766.0.html [Link added to main page of C34 Tech wiki]

[KWKloeber C-30 #3573]

Stu et al:

The iron/bronze Sherwood G908 is NLA. 
The replacement is the VERY expensive Westerbeke, which is a bronze pump.  I don't know who manufactures it but - just a guess - it might be the Korean pump.

Here's a helpful link for a pump rebuild for an Oberdorfer.  There is a Sherwood rebuild in the tech wiki but I'd opt to replace the Sherwood with an Oberdorfer because of all the dissimilar metals in a Sherwood.

Oberdorfer Pump Rebuild 101 - http://c34.org/bbs/index.php/topic,6766.0.html [Link added to main page of C34 Tech wiki]

[waughoo]

Any consideration for the JMP sherwood replacement or is that what you're talking about when you say the Korean pump?

https://www.jmpusamarine.com/products/jpr-wb7108-jmp-marine-westerbeke-replacement-engine-cooling-seawater-pump/

[KWKloeber C-30 #3573]

Yes, that's the 🇰🇷 pump.

Any consideration for the JMP sherwood replacement or is that what you're talking about when you say the Korean pump?

https://www.jmpusamarine.com/products/jpr-wb7108-jmp-marine-westerbeke-replacement-engine-cooling-seawater-pump/

[Pete G]

[/quote]
Just pull the impeller and shaft straight out and note the orientation of the tang on the end or the flat on the impeller end or mark a fin so you orient it correctly to put it back in.
[/quote]

I just replaced my impeller on the same pump (Oberdorfer).  There's really only one way it goes back together; the impeller and the shaft have a flat spot.  Mine had the paper gasket.  The hand-tightening bolts aren't stock.  Was the pump weeping around the gasket? 

[KWKloeber C-30 #3573]

There's really only one way it goes back together; the impeller and the shaft have a flat spot.
 

Just to be clear, the issue is leaking past the outer lip seal so he needs to pull and inspect the shaft, not just pull the impeller from the shaft.

When one tries to reinsert the shaft/impeller as a unit there's two locations (180 degrees apart) that the shaft fits back onto the camshaft.  If it's not lined up correctly it's difficult to rotate the impeller when inside the water chamber to get the shaft lined up with the camshaft.
 
That's why it's best to mark the position of the impeller when removing it.