Leaking raw water pump

[Trekka]

Additional to my other thread on leaking seacock.

The raw water pump on my Perkins 4-108 is leaking. There is a steady drip from a small hole under the shaft. When I run the engine the drip is stronger, almost a stream.

To be clear about what I am talking about: The pump is typical, maybe Jabsco? The impellor is in a housing the size of a tuna can, mounted on the front of the engine. The front has a speedseal cover. The back has a 1.5-2in shaft housing that has a base that bolts to the engine. Underneath the shaft housing, center, there is a small round hole where the drips originate.

What is likely to be happening here?

FWIW there is water coming out the exhaust, appears to be usual amount, but just guessing.

Thanks for any comments.

[cal40john]

Sounds like the shaft seal is going. This leak is a tiny amount of water compared to what is being pumped. The hole is to let water out when the seal goes bad. Here is a random Jabsco pump manual that shows a shaft seal replacement procedure. You should find the one for your pump model.

http://www.jabsco.com/files/18370_43000_0155_01_03.pdf

John

Originally Posted by Trekka

Additional to my other thread on leaking seacock.

The raw water pump on my Perkins 4-108 is leaking. There is a steady drip from a small hole under the shaft. When I run the engine the drip is stronger, almost a stream.

To be clear about what I am talking about: The pump is typical, maybe Jabsco? The impellor is in a housing the size of a tuna can, mounted on the front of the engine. The front has a speedseal cover. The back has a 1.5-2in shaft housing that has a base that bolts to the engine. Underneath the shaft housing, center, there is a small round hole where the drips originate.

What is likely to be happening here?

FWIW there is water coming out the exhaust, appears to be usual amount, but just guessing.

Thanks for any comments.

[Trekka]

Doing some reading on old threads suggests this may be a failure of the shaft seals. Or in a worse case, bearings going. (Wonder if that means bearings in the water pump?)

Guess I need to ID the pump on next visit. Maybe take in to a shop for the seals, or consider doing myself. (Always something new to do...)

[Trekka]

[Unfortunate that the site does not allow editing after 30 mins.]

Have an ID now: The pump is a Sherwood G65.

Where's a good source for parts at a good price?

cal40john, thanks for the link on procedure.

[cal40john]

Don't know about where cheap parts are, but here are the Sherwood G series assembly/disassembly manuals.

Sherwood Pumps Marine Distribution - References - References

John

Originally Posted by Trekka

[Unfortunate that the site does not allow editing after 30 mins.]

Have an ID now: The pump is a Sherwood G65.

Where's a good source for parts at a good price?

cal40john, thanks for the link on procedure.

[speciald@ocens.]

You probably can buy a repair kit containing seals and impeller. Check online. Changing the seals in not hard.

[Maddog]

Thank you, I have the same pump and the same problem. That link was great. Send it to Gord and have him put it with the other manuals.

[svHyLyte]

Unless I am mistaken, I believe one needs an alignment tool when reinstalling the raw water pump in the 4-108. There were several other posts on this subject in earlier threads on the matter that you might want to look up.

s/v HyLyte

[Trekka]

Interesting to see online new G65 pumps costing from $340 (discountmarinesupplies.com) up to $479...

But one of the more expensive outlets has the cheapest price for a "major repair" kit at $87:
www.pumpagents.com/SherwoodPumps/G65.html

Question: Could I service this w/o removing it from the engine? I have direct access to the front and sides of the engine. the pump is on the front, right side. Would that avoid the possible alignment issue mentioned by svHyLyte?

[Maddog]

On the alignment issue. I did the search as suggested and didn't find it. I've taken the G65 off my Perkins several time and have never had a problem. svHyLyte, If you have a link directly to the thread, I'd love to see it. I'm going to check the manual to see what they say. Trekka, I saw the saem deal at pumpagents and will be ordering the rebuild kit soon.I've got to belive that most of the price is in the bronze for the pump body.

[svHyLyte]

The following is excerpted from another discussion:

When I was purchasing the boat, my boat yard replaced the raw water pump before the sea trial. They destroyed THREE pumps in the course of two hours before figuring out there is a special procedure to prevent it.

The Perkins WORKSHOP manual states, verbatim:

"Should it be necessary to remove the sea water pump adaptor plate, it must be alighned on refitting by means of the tool shown in Fig. M.4.

To line up the adaptor plate, loosen the holding nuts and insert the tool in the water pump drive position to centralize the adaptor plate to the sea water pump driving shaft. Once the tool is located, the adaptor plate securing nuts should be tightened. The tool can then be removed and the sea water pump fitted.

To cover donditions where a centralizing tools is not available, the following interim measure can be taken.

Loosen the adaptor plate securing nuts so that they just support he weight of the sea water pump.

Rotate the engine two or three turns by hand: this will ensure that the adaptor plate/sea water pump will centralize to the fuel pump gear shaft. Then retighten the aaptor plate securing nuts.

It should be remembered that the latter procedure should only be used as an interim measure as it is not as accurate an alignment when using the tool previously described."

This info is not in the owner's manual, only in the WORKSHOP manual.

Referance to the foregoing alignment is also made in the Jabsco instructions. See Notice on Page 1 and reference on page 2 of http://www.jabsco.com/files/3270_000...bro_flange.pdf

I wish I could be more helpful.

s/v HyLyte

[Trekka]

I think I have the answer to the question of align-or-not.

The issue may be whether you just remove the pump,
or,
if you remove the pump and the mounting flange.

Found this: "... the pump mounts with 4 bolts to a flange which mounts with 4 bolts to the engine. If you just take the pump off, everything is OK, but if you loosen the wrong 4 bolts you will need to realign things or the pump drive will rapidly chew itself up."

I found that in an old post here, which I copied but did not save.
It appears to be in sync with the post of Perkins info:

"Should it be necessary to remove the sea water pump adaptor plate, it must be alighned on refitting

[Chief Engineer]

Depco Pump Company

[stephenmartin]

I had a similar problem with a Jabsco pump on a ford diesel....the bearings were worn and the shaft slapped about and destroyed the seals....the chandleries wanted to charge me an arm an a leg....until I found an old salt who said visit

BRT Bearings 240-242 London Road, North End, Portsmouth, PO2 9JQ, England
Telephone: 44 23 9266 9641


They supplied me with bearings and seals for about £10...$20 approx

[Maddog]

Originally Posted by Trekka

I think I have the answer to the question of align-or-not.

The issue may be whether you just remove the pump,
or,
if you remove the pump and the mounting flange.

Found this: "... the pump mounts with 4 bolts to a flange which mounts with 4 bolts to the engine. If you just take the pump off, everything is OK, but if you loosen the wrong 4 bolts you will need to realign things or the pump drive will rapidly chew itself up."

I found that in an old post here, which I copied but did not save.
It appears to be in sync with the post of Perkins info:

This makes sense.

svHyLyte - Thanks for brining the issue to light. I'm confident that I only removed the pump.