Yanmar 2QM20H water pump

[William parr]

I have a water pump that is showing wear on the cover plate and a little slake in the shaft do l completely rebuild are buy a new one🤦*♂️🤦*♂️🤦*♂️☹️☹️

[Wotname]

Originally Posted by William parr

I have a water pump that is showing wear on the cover plate and a little slake in the shaft do l completely rebuild are buy a new one🤦*♂️🤦*♂️🤦*♂️☹️☹️

Normally you would rebuild it. The bearings and seal are commonplace items and only a few dollars each. If the cover plate is too badly worn, you usually reverse it or if both sides are bad, machine it flat again.

I don't understand the meaning of little slake in the shaft but I guess you mean some wear or a grove where the seal sits.

If minor, this can be polished out and if beyond polishing, then fit a speed sleeve (AKA speed sleeve, shaft repair sleeve).

A new pump is very expensive compared to rebuilding one.

Can you post some pictures?

[William parr]

Sorry Wotname I mean the shaft moves forward and backwards just a little I figured that’s where that wear on the plate came from.I really appreciate your reply.Also are they very difficult to rebuild.

[Wotname]

Originally Posted by William parr

Sorry Wotname I mean the shaft moves forward and backwards just a little I figured that’s where that wear on the plate came from.I really appreciate your reply.Also are they very difficult to rebuild.

The wear on the plate usually comes from the impeller (over time) and is exacerbated by sand slit etc in the sea water.

For some folk, it is easy; for others, not so much.

However if you are reasonably handy, there is no reason you can't learn. Once you have done one or two, you will wonder what the fuss was about!

There are a couple of basic tricks to know about removing and more importantly refitting bearings - like never using a hammer on the inner race etc.

There has got to be a heap on youtube showing how it is done but commonsense will get you a long way down the path. There will be stuff on CF as well.

[William parr]

Thanks wotname for your help and time.Its a blessing to have people like you and this forum to turn to in time of need

[tkeithlu]

If you can't rebuild, a useful skill is searching the internet for the pump, rather than buying the part from Yanmar. The people who designed the engine did not design a propriatory pump. They took one out of industrial stock hat met their needs. Examples from the M25 diesel (Westerbeke) include the water pump, fuel pump, throttle, and starter, all available from other sources. The difference in price from Westerbeke versus an industrial source is often ten to one. Often Googling images for the item is a clue - different sources use the same photograph in their catalogs, so a pump that looks like the Yanmar catalog photograph may well be the same pump.

[George DuBose]

A quick look on the internet found several companies offering Johnson raw water pumps. Saw some on eBay also. Some gangsters in the UK are trying to sell the same Yanmar pump for over 900 pounds. Saw another British outfit offering an Anchor raw water pump the same specs as the Yanmar for 180 pounds.

My Yanmar 3GM30F has a Johnson pump.

Shop around...

[George DuBose]

Here is a US distributor for many water pump companies. They have my Johnson pump for my 3GM30F, don't know the pricing.

[George DuBose]

Here is a page from their catalog. It didn't attach at first.

[Boatwright]

If you don't want to do it yourself:

Flying Dutchman Water Pumps

Home

This shop will rebuild anything old or new. Reasonable prices, excellent services.

[Wotname]

Originally Posted by William parr

I have a water pump that is showing wear on the cover plate and a little slake in the shaft do l completely rebuild are buy a new one��*♂️��*♂️��*♂️☹️☹️

It is important to know that the raw water pump on the 2QM20H is directly driven (shaft driven) and not belt driven.

This means that a leaking pump can allow water ingress into the engine block. Of course there are several preventative measures in the design of the pump to stop this happening but as stuff wears, it can leak water into the engine.

There is a shaft seal, a "slinger" (usually just an O ring) and a weep hole to allow water to exit the pump before entering the engine.

The shaft seal will wear, the slinger becomes less effective with age and the weep hole can corrode up.

Keep an eye on this things and the pump will last forever (almost anyway )

See this thread about a similar pump on a similar engine
http://www.cruisersforum.com/forums/...ch-229225.html

[Disailor]

There are only a few mfgrs of bearings so when I needed to rebuild the Johnson pump on my 3YM30 I took the bearings to an auto parts store where they measured the outside dim/bore diam & thickness & looked it up by size. The smaller of the two is also used for the trans shaft bearing on a Chevy - $9!!. The shaft seal is also available for cheap (make sure it has a SS lip spring!-the original did not). Be very careful to note the sequence of the various spacers!

[Wotname]

Originally Posted by Disailor

......The shaft seal is also available for cheap (make sure it has a SS lip spring!-the original did not). Be very careful to note the sequence of the various spacers!

And if you can't source a seal with a SS lip spring (AKA garter spring), just get one with the carbon steel spring and remove the said spring and replace it with a O ring of suitable size.