Bears and seals for raw water pump

[sailorchic34]

So after a few weeks of casual looking, I finaly found a pesty water leak I've been having. Seems that my water pump">raw water pump on my yanmar 3gm30F has a bad seal in it. I really need to stay away of the muddy sloughs in the east bay area.

I've found a sourse for a new pump, but wondering if it might be less pricy to just take the bearings and seals to a bearing place. Gee it just about has to be.

So my question is, anyone happen to know the size bearings and seals in the 3gmf raw water pumps.

[lockie]

Is it the same as the pump on a 2GM? If so, I can send you the generic bearing and seal numbers. I also hate paying a 500% premium for the Yanmar part numbers!

It's pretty easy to rebuild these pumps. If you do it right, about the only Yanmar part you need is the impeller (and I'm sure there's a Jabsco or Johnsosn equivalent for that as well).

lockie

[lockie]

Have look at this post - it's all there (if your pump is the same as a 2GM)

http://www.cruisersforum.com/forums/...e-39471-2.html

lockie

[Badsanta]

Thats great to know. I just called to check on a rebuild kit for the 3gm30f and it was $185.

[sailorchic34]

Thanks Lockie!!! great help. Yes the basic raw water pump in the fresh water yanmar gm's are the same...

[Badsanta]

I have a sea cooling water pump kit for the 3GM30 that does not fit the 3GM30F. Seems that a raw water cooled is smaller than the F cooled version. Also a differance in the pre 1996 japam built compaired to the "E" version made in Europe.

[DotDun]

There is a difference in the raw water pumps on the 3GM30FC depending on where the engine was purchased. The YEU model has a different pump than the engine sold in the USA.

I have YEU model (no changeable cam) and both bearings, lip seal, and slinger are ~$55. A new pump is ~$225. The pump on the USA model is >$400.

So it's certainly worth rebuilding. The only other wear item on my model is the cover plate, but you should get several rebuilds before needing to replace/reface it.

Find out what you have and give Depco Pump a call, they have real humans you can talk to that know pumps!

Depco Pump Company: (727) 446-1656

[sailorchic34]

My back plate is still shiny inside. I sort of figured that the US might be different then elsewhere. I'm going to first try the local bearing place, and then depco.

FYI...Go2marine has the 3GM30F pumps for $300,

[DotDun]

Originally Posted by sailorchic34

My back plate is still shiny inside. I sort of figured that the US might be different then elsewhere. I'm going to first try the local bearing place, and then depco.

FYI...Go2marine has the 3GM30F pumps for $300,

If the bearing(s) are gone, that means the lip seal also needs replaced. Salt water will take the bearings out in short order (the slinger will protect 'em if the leak is small).

If the back plate (cover) is worn with deep groove it'll cause low output. I ground my down with 60 grit sandpaper on a Multimaster till the grooves are gone. If the cover doesn't have any writing on the back side, you can simply flip it.

I now have (2) spare pumps and simply change one when it leaks and rebuild it for the spare parts bin at my leisure. I've gotten as high as 900 hours out of one before needing rebuilt, average about 500-600.

Oh yeah, beware the nut on the front of the shaft is left-handed thread. I ruined a shaft before I figured that out.

Have fun!!!

[sailorchic34]

Thanks for the info Dotdun

[Stu Jackson]

And you should be able to rebuild, the bodies usually in good condition.

Not your pump, but here's how:

Mysteries of the Oberdorfer - Seal Replacement - REBUILDING A PUMP w/Flix

[sailorchic34]

Well I took the pump off and apart... The shaft is scored in two places (where the seal was resting on it one is minor but the other is about 8 thousands deep. I'm assuming 8 thousands is a little past the service limit. Bearing are a little loose, Looks like maybe rusty grease on the back bearing too....

So I'm going to need the pump shaft, bearings and seals.

[125Miles]

Also you can move shaft a fraction of an inch to one end or another, so new seal wont match existing groove and get away with replacing just seals and bearings. Just double check if there is enough space and usually there is.

[sailorchic34]

Well I did another experiment. I had read of someone just cleaning up the shaft and seal area and reinstalling it. I figured what do I have to loose. So I did do some light sanding along the scoring and reinserted the seal with a slightly different spacing. Put it all back together and reinstalled. Ran the engine for 10 minutes and not one drop leaked.

OH I'll still order a rebuild kit for sure. But for the $500 dollar cruisers, the el cheapo plan works too.

It really is very easy, so easy even blondes can do it.. Though pressing on new bearing will be a little fun. But I do have a big C clamp and access to a vise.

Happy girl..

Oh a head lamp (santa brought me one) really makes life easier when working on the engine in small places...

[DotDun]

Originally Posted by sailorchic34

Well I did another experiment. I had read of someone just cleaning up the shaft and seal area and reinstalling it. I figured what do I have to loose. So I did do some light sanding along the scoring and reinserted the seal with a slightly different spacing. Put it all back together and reinstalled. Ran the engine for 10 minutes and not one drop leaked.

Cool!

Originally Posted by sailorchic34

OH I'll still order a rebuild kit for sure. But for the $500 dollar cruisers, the el cheapo plan works too.

I find the bearings last a long time if you keep the saltwater off them. The lip seal only costs ~$5, hence for one on the cheap, maybe a routine change of the lip seal every couple hundred hours might make the $35 bearing set last longer. (just a thought)

Originally Posted by sailorchic34

It really is very easy, so easy even blondes can do it.. Though pressing on new bearing will be a little fun. But I do have a big C clamp and access to a vise.

No vice needed. I use a short 2x4 with a hole it the size of the shaft and tap the (protected) shaft with a hammer. Be gentle and it'll work just fine.

Originally Posted by sailorchic34

Happy girl..

Oh a head lamp (santa brought me one) really makes life easier when working on the engine in small places...

Yes, head lamps are the best invention!!!