3GM30F Raw Water Pump

[Mike Kegley]

Hoping to get a little assistance/clarification regarding sourcing a replacement raw water pump for my Yanmar 3GM30F as the pump appears to be leaking from the shaft seal. There seems to be lots of information floating around out there about what the proper pump for this motor is as well as greatly fluctuating costs between similar models. From what I have read I believe the pump is a Johnson Pump and comes in 2 different model numbers F4B-902 and F4B-903 with Johnson indicating on their website (http://www.pumpvendor.com/Yanmar_Pump_List.html) the full cam F4B-903 is a replacement for the reduced cam F4B-902. The 903 being $289 and the 902 being $632. Quite a difference!
I figured I would pull the pump and just go with the model it had on it but the model stamped into the body (4F-228) does not match anything I can find online and seems inconsistent with what other Yanmar owners have posted on forums.

I wouldn't think going with the full cam model and pumping more water would be a bad thing but that cost difference and some conflicting information floating around on forums has me saying hmmmmm.

Anyone have any additional insight on the topic?

Thanks
Mike

 

[Terry Cox]

Hi Mike, when the sea water pump on our first boat with a Yanmar 2GM was leaking through the shaft seal, rather than replace the pump, I ordered a new impeller kit that came with new seals, etc. and installed it myself. That fixed the leak problem. Perhaps that is all your 3GM sea water pump needs is a new set of seals and impeller. A Yanmar dealer in your area can get you the kit, or shop elsewhere, even this site might be able to help you.

 

[Calif. Ted]

I couldn't solve the puzzle myself either Mike, I went to Boatswains Supply, the Yanmar distributor for West Coast, old pump in hand. It took them at least 20 minutes because the part number had been changed several times, end result the new pump and a preformed hose were $632.
Right off the box, new pump genuine Yanmar Parts #721575-42702 that's off an '02 in a Catalina with the pulley in front and cover plate in the back, yours may be different ? BTW that's with pulley and bracket, makes it a simple remove and replace.
It may be possible to get just the pump for ~$100 less, but not from a Yanmar dealer, if you could get JUST the Johnson pump. I stopped looking, when you need a pump you take the one on the counter.

 

[kloudie1]

Seal can be easily changed it is a common part.. It is a 13287seal.. the numbers 13 is the inner diameter, 28 is the outer diameter, and 7 is the thickness in millimeters..While in there, change the bearings too .. they are standard 6202 2RS bearings that are readily available and inexpensive.. Bearings: https://www.amazon.com/6202-2RS-SKF...rd_wg=ljQm3&psc=1&refRID=DMFG9QBKM052P5GYAFBX
and seal: Yanmar 124223-42080.

 

[seadaddler]

Your pump is really not that hard to replace just the seal
and just recently helped a friend rebuilt his with a good vise.
Nick

 

[Ken13559]

Mike the leaking pump is easily fixed. All you need is the oil seal as given above. If bearing is not rusted and smooth, no replacement needed. Just remove the pulley and big C-clip. Knock the shaft assembly out from impeller side. Then push out the oil seal and replace it. Knock the shaft assembly back into housing using a proper size cylinder/pvc pipe over the large bearing. Put C-clip back and reassemble. Don't forget to rinse and grease the all parts before assembling. Its that simple. But if the bearings need replacing its a little more effort but very doable.
Just need to clean up the shaft (without scratching it) before putting all back. Use marine grease or Mobil XHP222 (blue color).
One trick I learnt from Youtube is to replace the spring of the Oil Seal with a similar sized n O-ring. You will notice when you open up the pump is the spring of the Oil Seal is badly rusted or gone. Perhaps that's why the shaft leaks. So the logic is with an O-ring, it'll never rust hence giving the seal a longer working life. If you do a search on Youtube for Dangar Marine, one of the video will show the O-ring replacement advise.
I've attached a How To instructions I've written to remind myself on how to repair the CW Pump. Age catching so cannot remember everything I did.... Hmmm....maybe that's a good thing.
Good luck.

PS: cost of repair probably $2 for the oil seal. It is next to the pump housing in photo.

 

[joker460]

Just my 2 cents worth. If you decide your pump can't be rebuilt you can get one from: http://www.depcopump.com/MarineCatalog-111/MarineCatalog111.html#/124/zoomed.
Just give them a call and they are really helpful. It has to be one of the least expensive pump suppliers.
Good Luck

 

[seadaddler]

I rebuilt my 3YM30 with info from Ken 13559 and just used over sized socket and round PVC and vise made things easy,but some older 2GM and 3GM use a different pump than what Ken info shows,did help a friend
rebuild his 1980 2GM and was different than mine but easy to rebuild and he got the rebuild kit from Yanmar
with all parts needed even new impeller and pump cover.
Nick

 

[Newport Bob]

Note that depending on version of the 3GM30F many parts are different- serial # starting with an E are Europe built.
See attached for part numbers

 

[markwbird]

If you don't want to rebuild it yourself which is not difficult try EBAY

 

[Mike Kegley]

Thanks to everyone for the wealth information. I pulled the pump apart and my internals are different than what is pictured by Ken. Mine is like this. http://www.pumpvendor.com/Yanmar_721575-42700_parts.html I have two 6202 bearings vs the two different sized bearings. The bearings feel good but there are two grooves in the shaft where the seals ride that concern me. I suppose it's worth a shot replacing the lip seal and the slinger and seeing how it goes.

 

[Jerry Clark H356 SV Persi]

I bought a new one from Pumpvendor.com a couple of years ago. Just checked the website and it is $289 and they have 16 available. It is the Johnson Pump. It is the exact pump you need.

 

[Mike Kegley]

Parts ordered. $15 dollars in parts and $16 for basic shipping. These are small parts...I can't help but think they are skimming some profit off of the shipping as well. Grr... Oh well.

 

[Mike Kegley]

Pump is back together and installed on the boat with new lip seal, slinger, impeller and gasket. I'm still concerned about the scoring on the shaft but I'll have to wait until spring commissioning to see if the new seal did the trick.

 

[Jerry Clark H356 SV Persi]

Hiw difficult was it to get the hoses off when you took it off? I've got to do this change out this spring and just wondering and what technique did you use?

 

[Mike Kegley]

The hoses came off pretty easy. They are right in front and are easy to get a grip on. Just remove the hose clamps and give the hoses a twist and pull. Loosen the nut on the pulley before taking the pump off the motor as you can use the drive belt to keep the pulley from turning.

 

[kloudie1]

The worn spot can be addressed either with a new shaft (721575-42501) Yanmar price about $130.. You may be able to take the shaft to a good small machine shop and have a new one machined for a little less, but that won't save much.. another option is the SKF Speedi-Sleave ,

price is around $30 for your shaft size..

 

[Mike Kegley]

Man, wish I would have seen this Speedi Sleeve option before I rebuilt my pump. I'll definitely consider it if the pump still leaks when I fire her up sometime in late March.

 

[Loyalist]

Oh My... I cannot begin to tell you how much I like this little tidbit. I have a 3QM and the shafts are impossible to source. All I need to do is spec and fit, AWSOME. Thank you for this.

 

[Jerry Clark H356 SV Persi]

Thanks for the Hose advice. Hope mine come off that easy.