Help, Perkins 4108 r/w pump

[Tom1340]

Hi forum,
Two weeks into my new-to-me boat (Hood 38), one week since launch, and I'm held to the dock by a leaky water pump">raw water pump (Jabsco 3270-0001). The leak is from the shaft seal, not the empeller cover. The parts list on this pump say the shaft seal is part of the standard minor service kit that comes with the replacement impeller. But Jabsco's service instructions say I need to remove the entire pump from the engine and pull the shaft and bearings in order to replace the water seal! This is no small effort.
Does anyone know if (& how) I can replace the shaft water seal with the pump staying on the engine.
Any help will be greatly appreciated.
Tom

[neilpride]

Probably taking off the cam and the wear plate plus the impeller , but if a seal fail is probably beter idea to dismantle the pump and check bearings and the other seal in the oil side to , is not so hard, is easy to dismantle and check shaft and other things. Cheers.NUMBER 10 IS THE SEAL, 14 AND 13 CAM SCREW AND CAM PLATE , THE WEAR PLATE IS UNDER THE IMPELLER BUT IS HARD TO TAKE OFF WITH THE PUMP IN PLACE, DONT USE SCREWDRIVERS HARD IN THE SIDES, TRY WITH A FINE PLIER.

[Dynamo1181]

Remove the pump for easy replacement. Caution!!!!...do NOT remove the mounting plate! If you do then removing the pump will be childs play in comparison.
A

[Tom1340]

Hi Alan, Neil,
I can remove the pump, no problem. But then do I need to remove the shaft and bearing assembly in order to push the water seal out. This seems a complicated step, as removing and replacing the shaft requires a press, which I don't have. Also, there is no evidence of problem with oil seal.

On the other hand, can I leave the shaft in, and tap the pump body to knock out the wear plate, then pull the old water seal out with a small screw driver and needle nose pliers?

If I have to find a press to remove the shaft, I'm probably better off buying new pump for $400.
If you've done this, tell me how you did it.
Thanks for your guidance.
Tom

[LJH]

Tom,

Congratulations on you new to you boat! We had out pump out and apart to replace the seals on the oil and the water side. We propped the pump up with two blocks of wood and tapped the shaft our with another piece of wood. No vice required.

Lyndon

[Jim Cate]

G'Day tom,

I too suggest that replacing the seal(s) or bearings in these pumps is an easy on-board job. If simple tapping does not shift the shaft, a simple bench vise can be used as a "yotties press", and has always sufficed to get mine apart.

Further, I suggest NOT buying the bits from the pump mfg, but simply taking the old seals to your local bearing and seal supply house for replacement. They are standard parts and will cost only a couple of dollars each. While you are there, you might buy some spares, and check out the replacement bearings, too. You will likely need them at some point, and they are only 6-10 dollars each.

Oh, have the chap at the bearing shop replace the little coil springs in the seals with an appropriate size o-ring... they don't rust out like the springs do!

Cheers,

Jim

[Dynamo1181]

Originally Posted by Tom1340

Hi Alan, Neil,
I can remove the pump, no problem. But then do I need to remove the shaft and bearing assembly in order to push the water seal out. This seems a complicated step, as removing and replacing the shaft requires a press, which I don't have. Also, there is no evidence of problem with oil seal.

On the other hand, can I leave the shaft in, and tap the pump body to knock out the wear plate, then pull the old water seal out with a small screw driver and needle nose pliers?

If I have to find a press to remove the shaft, I'm probably better off buying new pump for $400.
If you've done this, tell me how you did it.
Thanks for your guidance.
Tom

You can tap the bearing and seal out. I have rebuilt several in my 7000 hrs on our 4108. I keep a second complete on hand ready to drop in and rebuild the removed pump at my convience. I keep 3 or 4 seals and a bearing for spares.
Just dont remove that base plate!
Alan

[DeepFrz]

Maine Sail has a great photo article on rebuilding a water pump.

Rebuilding A Raw Water Pump Photo Gallery by Compass Marine at pbase.com

[Tom1340]

I pulled the pump off the engine. It was easy, as you guys said. I used LJH's technique for removing the shaft, also very easy. The bearings are good and so is the impeller, but the shaft is scored at the water seal lip.
If I can find a new water seal locally, I will put it in and see if it works. In either case, I'm also ordering a new pump.

Can anyone advise me on the gaskets on the impeller cover and pump-to-engine flange. Do you buy these or make them? Do you use a gasket dressing?
Thanks again for very useful info.
Tom

[neilpride]

Normally the Impeller gasket come with the new impeller in the box,for the engine side you can make one with gasket paper, if the shaft is bad scored you can use a small trick , in the pump where the lip seal rest in contact with the shaft , you can try to fit a thin washer of bronze or copper but need to be thin, later when you press the new seal in place the lip is making contact with a free scored shaft surface , i do that in one pump and it work , worth the try cuz a new pump is expensive, or do you try to found a new shaft? good luck..

[gts1544]

Tom1340, May I suggest that you look on E-bay before ordering a "new" pump! My 4-108 has a Sherwood pump and I was able to get a couple on E-bay very reasonably and carry them as spares. I am a big proponent of fitting the spare onto the engine and carrying the original as the spare. That way you know everything fits and works before you need it!

[Jim Cate]

Tom, it sounds like you are making progress! For the scored shaft there is another approach: There are numerous varieties of repair media for such situations... Speedy Sleeve IIRC is one particular one available here in Oz. At any rate, they are very thin sleeves of hard stainless that you simply slide over the shaft in way of the scored area. They renew the surface that the seal bears upon and restore original performance. Not expensive compared to a new shaft or entire pump, and available from your bearing supply house.

Cheers,

Jim

[Tom1340]

I found the lip seals, gaskets, and impeller at a local marine shop, and a shaft saver sleeve at a bearing shop. The pump was easy to rebuild with only basic hand tools It is back on the engine and tested out nicely. I'm good to go. Thanks for all the great suggestions.
Tom

[LJH]

Tom,

Good Job - time to get out and enjoy your boat!

Lyndon

[Allan S]

I had a dickens of a time getting parts for my Perkins 4-107 raw water pump. Very little co-operation from the dealers from around here. Sourced everything out piece meal and recorded all part numbers.

The three Perkins dealers wouldn't help me because I had "too few" engine numbers. Well, I did some research on the internet, (Did you know there was more than naked girls on the net?), and found out that for my engine, I just had to add two letters to the start of my engines serial number.

My Sherwood pump had no model number, I tracked the casting numbers on it and found out it was obsolete, but found alternative repair kits and even sourced an alternative pump.

What I learned in this whole endeavor is that business, no matter what the economic situation is, are only looking for the big score, and the low $100 I'm willing to drop is not worth their time. Well, I say "F*ck them", I sourced everything cheaper.