leaking raw water pump

[Bill Root]

The Sherwood 17000 series water pump on my starboard engine is leaking through the weep holes at the front of the pump. I first noticed the leak about 700 miles into our 6,000 mile Great Loop journey when salt water began to accumulate under the engine after a day's run.

I stopped in Deltaville, Va. to have the pump repaired. I decided while I was at it to have major rebuilds done on both the starboard and port engine pumps, since this had not been done since I bought the boat two years ago. Both pumps ran fine and were leak-free for about two days, then the starboard pump started leaking again from the same place. By then I was 200 miles away from Deltaville, too far away to return. I'm tied up now at a marina in Upstate NY for a week visiting friends. While here, I would like to try to repair the pump myself, since my friends have ample tools and work space.

Since I don't know for sure what parts the mechanic actually replaced, is it possible he just did the impellers and did not do the rest of the seals, etc. that would cause the leak through the weep holes, or could faulty parts installation cause the pump to be leak-free for only a short time? I don't want to spend $800 on a new pump if I don't have to, but also don't want to throw another $200 into this pump for major rebuild kit if it isn't likely to fix the problem. The pumps are on a pair of factory rebuilt CAT engines that were put into the boat about six years ago. They have 400 hours on them now.

The expert advice of this group would be appreciated.

 

[REBrueckner]

Since I don't know for sure what parts the mechanic actually replaced, is it possible he just did the impellers and did not do the rest of the seals, etc. that would cause the leak through the weep holes, or could faulty parts installation cause the pump to be leak-free for only a short time?

di9sappointing; try another mechanic////

likely either situation is the cause, although I do not know your specific pump....Always ask for the old parts...that way the mechanic has some incentive to do the work paid for and you get to ask what was wrong via inspection of old parts.
400 hundred hours is NOT much run time, buit of course they may not have been rebuilt with the engines....

A dripping pump by the way does not harm except that the salt water corrodes the engine or tranny under it....You might be able to wrap a piece of plastic around the pump if any water is being flung about and perhaps put a diversionary plastic container under it or maybe a piece of water repellent material so the water dribbles directy to the bilge...

You might also consider having the one pump rebuilt and purchasing a new one...carry the rebuilt as a spare...assuming a pump can be used for either engine....

I assume these are gear driven not belt and pulley...too much belt tension can ruin pump bearings...but not normally THAT fast...

 

[sammidog]

I would think if he just replaced the impeller it would have leaked from the start as the "problem" would never have been fixed. I'm not familar with that pump but are you sure it is leaking from the weep holes and not leaking somewhere higher up and ending up there?

 

[Bill Root]

I am certain it's leaking from the weep holes. I've seen it drip. The water coming out is brown. It drips onto the left front motor mount then onto the oil absorption pads under the engine. The brown stuff stays on the pad, the water weeps through and winds up in the bilge as clear salt water. By the way, I was told that if the pump continues to leak at the front it will eventually ruin the pump bearings.

 

[captddis]

The brown water is actually rust from the bearings mixed with water. The bearings are already toast. If you have a Cummins pay the money for a Seamaxx pump. If you have Cats, Cat has a very good deal on reman exchange pumps. Do not ignore it as when the bearings fail, the drive gear can cock and take out the front gear train.

 

[Reelin]

I believe SEAMAX also makes the Cummins pumps to fit Cat's. The Sherwood Pumps are a piece of garbage. Go over to Boatdiesel.com and there is a lot of info about them. Give Tony Athens a call at Seamax and he will set you straight.

 

[captddis]

No , Tony told me that he sees no reason to make pumps for Cats as their factory remans are so reasonable.

 

[BUSTER]

Whatever you decide to do......Do not run the boat anymore than absolutely necessary. Any saltwater that can be misted in the engine room will end up running through your engine. I have a good example of it on the engine stand in our shop right now. The owner said it was only a steady drip,so he ran the boat a few weekends until he got around to replacing the raw water punp. That was the end of last season.This season,the heads came off,the valves and combustion chamber were salt damaged along with the pistons and I am now rebuilding the entire 5.9 Cummins.

 

[Bill Root]

Thanks for all the excellent advice. It sounds like a remanufactured pump from CAT is the way to go. I have no plans to move until Sunday, so hopefully I can find a way to get the pump and install it by then. Does anyone know someone I could call to get a pump? I'm near Syracuse in Upsate New York.

 

[Canuck Dennis]

Sherwood pumps are indeed garbage, a complete rebuild kit usually costs as much as a new pump, I have one on one of my gensets and next leak it goes in the garbage.

 

[captddis]

Thanks for all the excellent advice. It sounds like a remanufactured pump from CAT is the way to go. I have no plans to move until Sunday, so hopefully I can find a way to get the pump and install it by then. Does anyone know someone I could call to get a pump? I'm near Syracuse in Upsate New York.

I would call the nearest Cat distributor and see if you can pay with a credit card and have it shipped to your marina. You will have to ship the core back. I think HO Penn or Southworth Milton are distributors in the area.

 

[fissioneng]

Any saltwater that can be misted in the engine room will end up running through your engine. I have a good example of it on the engine stand in our shop right now. The owner said it was only a steady drip,so he ran the boat a few weekends until he got around to replacing the raw water punp. That was the end of last season.This season,the heads came off,the valves and combustion chamber were salt damaged along with the pistons and I am now rebuilding the entire 5.9 Cummins.

This sounds a bit extreme. Any saltwater in the engine room will destroy your engine in a few weekends? By misting, you mean spraying on rotating machinery? What about spray from bilge water spraying around the shaft?

From your description, it sounds like the engine ingested saltwater. How do you have a boat in saltwater and not have a salt environment in the engine room?

 

[BUSTER]

Saltwater dripping from a rotating propshaft with a boot fitted ovr the top half is not a problem,that's why knowing owners fit a boot,to minimize salt damage to the electrical system and the engine. Saltwater dripping onto a belt,sheave or balance wheel,saltwater spraying from a pinhole in a hose,may become airborne and find it's way into the air intake of your engine.If it does,the consequences are often serious.Turbochargers,aftercoolers,valves and pistons are the most susceptable to this damage and we see it often in the marine engine repair business.

Last year we rebuilt a Volco TAMD for an ownwer that removed the engine and brought it to us.We test stand-ran it for several hours. He reinstalled the engine and we commisioned it. All was great.Later in the season he called me because the motor was suddenly sluggish.I went down to his boat and found the Air-Sep filter clogged with salt.It seems he forgot to put his dorades "that he had removed to repair" back in the engine room,ran in a big beam sea and salt water ran through the engine. After a lot of cleaning,then running a garden sprayer of warm soapy,freshwater slowly through the engine at a fast idle,she ran well. So far this year his engine is still running well,after we replaced the belt driven supercharger,"the vanes were salt damaged" but I promise you that incident took a lot of life from that engine.

 

[BUSTER]

Thanks for all the excellent advice. It sounds like a remanufactured pump from CAT is the way to go. I have no plans to move until Sunday, so hopefully I can find a way to get the pump and install it by then. Does anyone know someone I could call to get a pump? I'm near Syracuse in Upsate New York.

In your area,I would call Southworth-Milton CAT.

 

[REBrueckner]

"Saltwater dripping from a rotating propshaft with a boot fitted ovr the top half is not a problem,that's why knowing owners fit a boot,to minimize salt damage to the electrical system and the engine. Saltwater dripping onto a belt,sheave or balance wheel,saltwater spraying from a pinhole in a hose,may become airborne and find it's way into the air intake of your engine."

Great advice and 100% correct...it's the same reason I posted that putting a piece of plastic over any raw water pump (to prevent salt water spray) is always a good idea. It may take sveral weeks of use before an owner/operator realizes a leak exists and by that time spray mist and salt may have taken their toll. Several Jabsco raw water pump models on 53 and 71 series Detroits have an open slot just perfect to hold such a retainer and prevent spray.

And with the Sherwood pump in question, if the drip is already brown seems a good chance the pump was not rebuilt....

Detroit 71 series JABSCO pumps have a slip ring (not the correct name) so if the pump develops a leak water is supposedly restricted to the weep hole instead of doing damage...Do Sherwoods have a similar protection??

 

[dsharp]

http://www.sherwoodpumpsdistributio...ne-Distribution/en-us/MPG_3045_17000_TECH.pdf Some people try to replace the seal without removing and cleaning the pump shaft. I think it's part #15 in the diagram, but, you have to press the seal in without chipping the ceramic surface. The face of the seal is brittle and not hard to chip during installation. If the pump has been dripping for a while it will build up scale on the shaft which will also cause them to leak.

 

[Bill Root]

I found Milton CAT in Syracuse. They got me a remanufactured pump with warranty for about $250 with core exchange. The re-build kit would have been $190. Yet again, this forum saved me a bundle.

By the way, Sherwood is the spec pump for this engine.