YanMar 3GM30F water pump impeller

Robin

Robin

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I can get a spare impeller easily from West Marine here but it doesn't come with a gasket. Is it a simple thin paper gasket or an O-ring seal please on this engine? am i right in thinking this is a Johnson pump? I just want to have some basic spare on board.
 
TradewindSailor said:
Hi Robin

Yours should have a paper gasket ..... although you can probably use liquid gasket in a pinch. http://maiaaboard.blogspot.com.au/2013/04/yanmar-3gm30f-raw-water-pump-rebuild.html
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Thanks. I could probably make a paper one except I know of old on other engnes the gasket thickness is important also, in order to get a proper seal of impeller side against faceplate, too thick and it can suck air i and not self prime, it might be difficult to use a liquid gasket goo for the same reason, but with luck the old gasket would come away intact, but I never get that lucky.:disgust:
 
The one that came with my my impeller was the wrong shape for some reason so I made one from a glossy magazine cover on my 2gm20. worked fine with no leaks.
 
It's really annoying that Yanmar (and all the others) insist that a new gasket should always be fitted, yet they sell the impeller without one! As it happens, I've been lucky in that the faceplate comes off leaving the gasket in place, unbroken. I do the business with the impeller and then smear a little grease on the gasket and replace the faceplate - so far no signs of leakage. Bearing in mind the parts all wear, so thickness is an approximation, a reasonable match of gasket paper should be OK and useful to have on the boat for other jobs.

Rob.
 
rob2 said:
It's really annoying that Yanmar (and all the others) insist that a new gasket should always be fitted, yet they sell the impeller without one! As it happens, I've been lucky in that the faceplate comes off leaving the gasket in place, unbroken. I do the business with the impeller and then smear a little grease on the gasket and replace the faceplate - so far no signs of leakage. Bearing in mind the parts all wear, so thickness is an approximation, a reasonable match of gasket paper should be OK and useful to have on the boat for other jobs.

Rob.
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I'm happy to carry some suitable paper but guessing the thickness before removing the cover is a bit hit and miss. Do I Need golf monthly mag paper, a bit of brown wrapping paper ( years ago I soaked some of this in oil to use as gasketing paper..) or is it Sunday times supplement cover paper or the Mail on Sunday one? we get none of them anyway here in Florida!
 
rob2 said:
It's really annoying that Yanmar (and all the others) insist that a new gasket should always be fitted, yet they sell the impeller without one! As it happens, I've been lucky in that the faceplate comes off leaving the gasket in place, unbroken. I do the business with the impeller and then smear a little grease on the gasket and replace the faceplate - so far no signs of leakage. Bearing in mind the parts all wear, so thickness is an approximation, a reasonable match of gasket paper should be OK and useful to have on the boat for other jobs.

Rob.
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All the Volvo impellers I have bought have come with a new gasket, though with a Speedseal they are unused.
 
Robin said:
So somewhere you have a few gaskets you could sell?? my bet is they re all pretty much the same. I thought a Speedseal would be good to have too but haven't seen them on sale anywhere over here.
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I thought a Speedseal would be good too, but I have the wrong size of pump to be able to fit one.....on my 3GM30 the pump is about 2 5/16" across and Speedseal only make one to fit a pump housing of about 2 3/4" - somebody will probably be able to tell us which make of pump relate to those sizes.

Anyway, when I bought replacement impellers recently they actually came with gaskets (although too big for my smaller housing). I just cut them to fit, which was a bit hit and miss, but so far no leaks. By the way, it was more 140g/m2 thickness, with standard A4 photocopier paper being about 80.

Pladda
 
Pladdatoo said:
I thought a Speedseal would be good too, but I have the wrong size of pump to be able to fit one.....on my 3GM30 the pump is about 2 5/16" across and Speedseal only make one to fit a pump housing of about 2 3/4" - somebody will probably be able to tell us which make of pump relate to those sizes.

Anyway, when I bought replacement impellers recently they actually came with gaskets (although too big for my smaller housing). I just cut them to fit, which was a bit hit and miss, but so far no leaks. By the way, it was more 140g/m2 thickness, with standard A4 photocopier paper being about 80.

Pladda
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Thanks, that just saved me making a $100 mistake! maybe some classy printer paper will be about right to use. Can you reach your impeller housing? On ours ( Benny oceanis 36cC centre cockpit) it is accessed from a stern cabin but it looks like the bracket holding the pump has to come off, with the pump still attached to do the job. poor design by yanmar for sure.
 
Robin said:
Thanks, that just saved me making a $100 mistake! maybe some classy printer paper will be about right to use. Can you reach your impeller housing? On ours ( Benny oceanis 36cC centre cockpit) it is accessed from a stern cabin but it looks like the bracket holding the pump has to come off, with the pump still attached to do the job. poor design by yanmar for sure.
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Pleasure.............and no I can't reach my impeller housing without getting a hernia !

There was a Turkish fella doing an adjustment kit which relocated the housing to be forward facing, but I emailed him recently, and got no reply, so I think that option no longer exists.

See this thread: http://www.ybw.com/forums/showthrea...p-relocating&p=4666778&highlight=#post4666778
 
I have recently replaced the water pump on my 2GM20F and apparently depending on the year the engine was manufactured it could have either a gasket or an O ring. luckily mine was the one with the O ring. If you remove the your cover you will soon find out.
I would be careful just carrying a spare impeller without actually checking it is the exactly the right one though, from what I have read there may-be slightly different sizes of pumps available also (I can't confirm this)

When I was looking on the internet for Yanmar pumps I found this and saved it.


- Went to Yanmar distributor with old pump in hand and a pair of calibers to measure inner chamber diameter, as well as Cam size.
- Didn't need calipers to see the cam size on new pump was 2 to 3 times thicker than original pump!
- Yanmar agent insisted the pump I had was the one for the fresh water (3GM30F) model and that the 3GM30 raw water pump is a smaller one he showed me.
- However, smaller Yanmar branded pump was ~€500. And exact "like for like" replacement of my bigger Johnson pump was "only" ~€220.
- So a bit of a surprise/confusion, but was reluctant to pay twice as much for a smaller pump.
- Was more logical to get the same pump that had worked fine for 13 years.
- The main thing was seeing the Cam size in the new pump. I will attach pictures.
- Note: the cam in both pumps are not replaceable... (else I would have fixed this last year!!!)

New Johnson pump specs compared to old pump:
- Yanmar p/n 128397-42500

Old Pump: Johnson Pump F4B-902, 10-24509-02. Impeller Johnson 810B.
New Pump: Johnson Pump F4B-903, 10-24509-01. Impeller Johnson 810B-1. (no paper gasket)

Old pump Inner chamber diameter: 50.2 mm. Diameter to cam: 48.25 mm.
New pump Inner chamber diameter: 50.0 mm. Diameter to cam: 46.00 mm.

Pete
 
pete said:
I have recently replaced the water pump on my 2GM20F and apparently depending on the year the engine was manufactured it could have either a gasket or an O ring. luckily mine was the one with the O ring. If you remove the your cover you will soon find out.
I would be careful just carrying a spare impeller without actually checking it is the exactly the right one though, from what I have read there may-be slightly different sizes of pumps available also (I can't confirm this)

When I was looking on the internet for Yanmar pumps I found this and saved it.


- Went to Yanmar distributor with old pump in hand and a pair of calibers to measure inner chamber diameter, as well as Cam size.
- Didn't need calipers to see the cam size on new pump was 2 to 3 times thicker than original pump!
- Yanmar agent insisted the pump I had was the one for the fresh water (3GM30F) model and that the 3GM30 raw water pump is a smaller one he showed me.
- However, smaller Yanmar branded pump was ~€500. And exact "like for like" replacement of my bigger Johnson pump was "only" ~€220.
- So a bit of a surprise/confusion, but was reluctant to pay twice as much for a smaller pump.
- Was more logical to get the same pump that had worked fine for 13 years.
- The main thing was seeing the Cam size in the new pump. I will attach pictures.
- Note: the cam in both pumps are not replaceable... (else I would have fixed this last year!!!)

New Johnson pump specs compared to old pump:
- Yanmar p/n 128397-42500

Old Pump: Johnson Pump F4B-902, 10-24509-02. Impeller Johnson 810B.
New Pump: Johnson Pump F4B-903, 10-24509-01. Impeller Johnson 810B-1. (no paper gasket)

Old pump Inner chamber diameter: 50.2 mm. Diameter to cam: 48.25 mm.
New pump Inner chamber diameter: 50.0 mm. Diameter to cam: 46.00 mm.

Pete
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NOw I really am panicking! I just wanted to carry a spare on board, just in case. The boat is a 1998 French built one even though we are in the USA where some were built here. The first OMG IS That the pump is inaccessible without removing it from the engine, next OMG is that even if you find a source for the impeller they don't come with a new gasket. I have to pay an engineer to do the work on our engine as I'm still finding such jobs awkward after a stroke so simply removing it to check stuff beforehand is a PITA and a min charge $100 from Mr. engineer.

THIS should not be that difficult and I am revising my previous excellent opinion of Yanmars by the minute!
 
We have a 3GM30F fitted, along with a 'Speedseal' face-plate and that item's definitely a waste of time/money; to get at the impellor properly (and more quickly) you're better off to unbolt the bracket, disconnect both hoses and remove the whole unit, to be fair, I suppose at this point, undoing the knurled screws rather than using a screwdriver would probably save a few seconds? Though the screwdriver you'd used for undoing the hose clamps will fit and is already out of the toolkit anyway.

We have a complete spare pump - I know, flash git! - so on the one occasion we broke an impellor blade, it was just a switch-over job; that spare pump does have a 'standard' face-plate fitted and seals/works perfectly with just a smear of silicone sealant on the joint face; I no doubt have some of the appropriate/proper paper gaskets somewhere, but they weren't handy when I was putting it back together and the silicone was, the gasket is/was a very thin one, so don't fret about 'spacing'.
 
Yanmar engines with EU at the end of their code were 'assembled' in Europe to avoid paying import duty on them. Assembly consisted of fitting a water pump. Two types that I know of were fitted, the covers have different shapes and are not interchangeable, neither are their cover seals. You need to take the old cover when buying new to ensure they are the same.

If you remove the holding bolts it is perfectly possible to turn the pump around to remove the cover without disconnecting the hoses. There is plenty of slack in them.
 
Robin said:
NOw I really am panicking! I just wanted to carry a spare on board, just in case. The boat is a 1998 French built one even though we are in the USA where some were built here. The first OMG IS That the pump is inaccessible without removing it from the engine, next OMG is that even if you find a source for the impeller they don't come with a new gasket. I have to pay an engineer to do the work on our engine as I'm still finding such jobs awkward after a stroke so simply removing it to check stuff beforehand is a PITA and a min charge $100 from Mr. engineer.

THIS should not be that difficult and I am revising my previous excellent opinion of Yanmars by the minute!
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They're ok, Robin.
Robin could I ask what you paid for your impellor? I've previously changed mine every year but stopped doing so 2 years ago (I recycle the old ones) when the UK Yanmar dealers wanted £45 for one.

Vyv's post reminded me to ask if your impellor has a keyway? Mine has and it is something to do with EU ....
 
I have sort of come to the same conclusion re the speedseal for our application which is a pity as it looks to be a perfect solution on most boats/engines. My concern over paper gasket thickness dates back half a century probably to when I had crappy little Volvo MD1s in a variety of boats where worn faceplates and overthick homemade gaskets did factor. I remember I solved one faceplate problem by turning the plate over and another by purchasing a new one. I just found a source for a new (Yanmar OEM) impeller and gaskets and these are being mailed to me from Fort Lauderdale as there is nobody here in Daytona that stocks them, the penalty of living in the third world, lots of boats, very few competent supply places locally, even the nearest sailmaker is some 100mls away so our new main was shipped over from the UK, cheaper and better.
 
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