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Water Pump Leak Advice

How difficult is it to replace the gasket between the pump and the engine block? Where can I buy the proper gasket? I can see where I have some saltwater leakage. Is it necessary to rebuild the entire pump? It is not that old but I did have some excessive engine heat for a while. Temperature got up to 200 degrees, normally runs at 140. Had an engine exhaust leak which caused the engine room to get hot, hot enough for my Fireboy to self-discharge. Got the exhaust leak repaired and she ran beautifully another 800nm (75% motoring).
 

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When I've had water leaks in my Jabsco raw water pump, it wasn't at the place where the pump mounts on the engine but just behind the impeller housing. I had to replace the whole thing but that's because I didn't have the tools nor skills to rebuild it. I was able to get the old one rebuilt by a mechanic but the cost wasn't much cheaper than the new one. I've had oil leaks however, where the pump unit meets the engine but that was because a different mechanic failed to properly remove the old gasket and the slight bulge allowed oil to leak. Your leaking doesn't look like oil. Anyway, the gasket came with the new pump (from Trans Atlantic Diesel) but I am pretty sure if you Googled the manufacturer and model number of yours, you'd probably find someone online that sells an appropriate gasket. Removal and replace are straightforward. Unbolt and re-bolt. Just be sure to scrape away all bits of the old gasket before putting the new one on.
 
Hi Marc, I agree with Ken on the leak it looks like saltwater. If it is a Sherwood pump there are three possibilities.
> The cover gasket is leaking, make new gasket.
> The impeller compression retainer screw is leaking,remove and add plumbing sealant to it.
> The third and most likely the housing has two weep holes drilled in the casing. If water gets past the water seal it will leak out the hole. If oil leaks past the oil seal it will leak out of the hole. The two holes are in the same plane so I am guessing for different mounting possibilitie?
Like Ken said you can by a new or rebuilt pump, the parts along will cost half the price.
 

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Critical check!

I just went through this, and it turned out that it wasn’t the raw-water pump at all ...

The wet-elbow had corroded shut ...

Which meant the pump was trying to do the impossible by pumping water against infinite resistance!

Apparently this is pretty common ...

So, check for this first...

Easy test:

Disconnect the output hose from the raw-water pump, try to blow through it - it should be easy.

If you can’t blow through this hose, neither can the pump push water through it,

it means you’ve got a blockage down-stream, in the heat exchanger, the exhaust-manifold water jacket, or the wet-elbow ....

My mechanic told me it was most likely the wet-elbow, and - sure enough - that was the problem.

Put in a new wet-elbow, and the pump no longer leaks.

Try this before disassembling the pump ....
 
I should add that water can still be getting through, so just checking for water coming out the exhaust is not enough ....

The pump can still be trying to push against too much resistance, even if the circuit is not completely blocked....

It should be easy to blow through the hose ...
If not, there’s a major block ...
 
Can you see where the water is coming from when the engine is running? My guess is the seal at the back of the impeller housing as well (as suggested by Ken and Rick above). I just put a new seal in my pump last week. It's not hard, but it's easy to mess up a seal if you haven't done it before. You can press the pump apart using a c-clamp or vice and a large socket. Make sure the shaft is clean and smooth, I sanded mine with some 2000 grit just to make sure it didn't have any burs. Pop the old seal out and gently tap the new one in with an appropriately sized socket. When removing the pump make sure to only remove the 4 bolts holding the pump to the adapter plate, not the adapter plate itself. If you remove the adapter plate you'll need the alignment tool to re position it.

You can get all variety of rebuild kits here, you might just need the "service kit" which is only $35.
https://www.parts4engines.com/perkins-4108-raw-water-pump-impellers-service-kits/
 
Hey Marc, I have a slightly different layout but I had a similar leak on my pump in the Summer of 2014 and I replaced with a new one and kept the old for having rebuilt... someday... haven't gotten around to it. I do remember being warned NOT to remove a mounting plate that the water pump bolts onto... apparently it is a centering device for the drive gear to be balanced with the input shaft of the pump.
Also, I took off my mixing elbow on the aft end of the engine... 4 bolts and it was off.... I ran barnacle buster thru it and ran some wire down in those passages to be sure I have good water flow all around the casting and now I do. I was running a little hotter than normal on our trip down to Captiva... also had the runaway on the motor and diesel dilution of the motor oil which I posted about. Everything is pointing to the diesel in the oil being caused by a partially perforated manual lift pump (on engine starboard side, runs off of the engine camshaft). I have a brand new one in the box and am heading down to the boat in the morning to change the oil, get the new lift pump on and clean out the raw water cooling side of the engine heat exhanger with barnacle buster and replace the antifreeze coolant.
 
Getting back to this project. It was suggested I make a replacement gasket. This is for the gasket that goes between the pump and the engine. Is that material generally available at an auto supply store? What is it called? Is it installed with any gasket sealer? Can I buy just that gasket? Wonder why that doesn't come with the impeller kit.
 
If ypou replace the impeller ask about a" Globe" run dry impeller . Just a better impeller its Blue Poly not rubber.
 
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Marc,
If you haven't already dealt with the gasket...
Different types of gasket materials are readily available at most real auto parts stores. A good NAPA or equivalent should have fiber, cork, rubber types in sheet form.

I'm not sure what type you will need, or the thickness. I'm also unsure, but imagine the gasket shouldn't be to thick or your pump may not be effective. Another route may be a sealant such as "The Right Stuff". Made for engines. Comes in small tubes or caulking gun type tubes. This is one of the best sealant that we use for many jobs in my shop.
Kinda think like silicone but not. It works!

Mitchell
 
Well, got the pump all prettied up, used "Right Stuff" sealer only to discover now I have a leak from one of the drain holes, which wasn't leaking before. Got her off but having trouble finding a shop in town to rebuild it. Is this ever going to end? Did someone post instructions on DIY rebuilding? I can't find that anymore. Please repost.



UNADJUSTEDNONRAW_thumb_8767.jpg
 
This is consistent with blockage further on in the circuit.

Did you try the test I suggested above?

If the pump cannot push water through the system, the pressure inside the pump will easily build up high enough to overpower the weakest seal.

Since you just improved one seal, the shaft-seal may now be the weakest, so it is overpowering that, leading to water coming out the weep hole.

My pump was squirting water all over the place before I discovered the block in the mixing-elbow.

Having replaced that, the pump is not leaking at all.
 
Thanks Chris. I will give it the blow test but when I had to replace the pipe that the elbow attaches to the engine with (after it ruptured and filled the boat with smoke) the mechanic did say he thought the elbow would need to be replaced in the future. He must have seen corrosion. Looks like it might be time. Then I can go back and see if the water pump need rebuilding!

Any ideas where I can find a replacement elbow? I hear the manufacturer doesn't make them and I have to go with an aftermarket one. I've struck out so far trying to find one.
 
Thanks again Chris. I gave it the blow test and it flowed easily, so i think my problem might be my pump seal after all, but since I had a mechanic tell me the elbow would need to be replaced in the near future I decided to pull it out while I'm here. Ben at exhaust elbow says he can build me a replacement in a couple of days so I'll do that.

Still looking for those instructions on rebuilding the pump, if anybody has a copy they can repost. I would like to tackle that this week too. Also, any advise on what parts I'll need would be appreciated.
 
You tube How to repair 4108 water pump . A good source for 4018 gaskets and info is Trans Alantic Diesal . Very good web site and 50% cheeper than Folley !
 
When i had my 28 Sabre the exhaust elbow blew a hole in it . A volvo engine and Volvo watned 400 pluss just for the part. So i went to the blog Sabre they said home depot black cast iron so i made a U from cast iron parts and screwed it all together. i took it to a local guy who would cerimic coat the inside pieces.!
It worked great I had it another 7 years before i traded her in for the morgan .
 
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