Change water pump?

[pbyrne]

Noticed this discolouration under the water pump (I believe), and thought I'd ask here is there is something to be concerned about.

The engine has less than 900 hours on it, and I've never found any water there, but clearly something is going on.

Thoughts?

[Ron Hill]

pby : I make a small wad of toilet paper and stuff it in the bottom weep hole of the Sherwood. Run the engine a bit and then check that wad for wetness. Also check around the hoses leading to and from the Sherwood

A few thoughts

[pbyrne]

pby : I make a small wad of toilet paper and stuff it in the bottom weep hole of the Sherwood. Run the engine a bit and then check that wad for wetness. Also check around the hoses leading to and from the Sherwood

A few thoughts

Will do! As always thank you Ron.  I'm assuming this weeping hole is there to alert you to something that needs fixed? 

[KWKloeber]

The telltale weep hole is sending you a silent Mayday that the pump seal is leaking.

How tight is the engine belt?  Within spec/too tight?
Remove the belt and see if the shaft will wobble.  The pump seal and shaft and bearing can be replaced but the cost of getting the pump serviced might not be worth it compared to a new one.

There is an oddity on the B engines -- there are two different Kubota pumps with different P/Ns
and impeller sizes.  Apparently, the pump capacity was insufficient and the impeller size was increased, which necessitated a whole string of changes at the front end of the engine.

Take your old mump to the dealer to match it up to be sure.

If instead you want to order the rebuilding parts they are in the Kubota parts manual on the TechWiki.

[waughoo]

Thanks Ken for all those details. Mine is nice and dry at the moment but I am making note for the inevitable future!

[KWKloeber]

Thanks Ken for all those details. Mine is nice and dry at the moment but I am making note for the inevitable future!

I found a C36 couple who replaced theirs w/ a Kubota -- but naturally never put the correct part number in their blog -- only explained that there were two sizes.  ARRRRGH! 

That's when you know someone is trying to hear themselves talk rather than wanting to help others. 

[Ron Hill]

pby : Yes, the weep holes are there to let you know that water OR a oil seal needs to be changed!! 

A thought

[pbyrne]

Thanks Ken for all those details. Mine is nice and dry at the moment but I am making note for the inevitable future!

I found a C36 couple who replaced theirs w/ a Kubota -- but naturally never put the correct part number in their blog -- only explained that there were two sizes.  ARRRRGH! 

That's when you know someone is trying to hear themselves talk rather than wanting to help others. 

Is this it? https://www.gciron.com/Kubota_Parts_16241_73037_PUMP_WATER_ASSY_p/ku-16241-73037.htm

[pbyrne]

pby : Yes, the weep holes are there to let you know that water or a oil seal needs to be changed!! 

A thought

I put the wad in but it fell out, and was dry.     Not sure when it fell out.

I did touch the weep hole and I felt nothing, so I don't understand where the discolouration is coming from.  If it was truly weeping, wouldn't it be obvious?

[pbyrne]

The telltale weep hole is sending you a silent Mayday that the pump seal is leaking.

How tight is the engine belt?  Within spec/too tight?

I can rotate the belt 90 degrees on the longest run of the belt, and if anything might be a touch loose as it seems to deflect more than 1".  But there's no squealling and charging and exhaust water seem to be as expected.

[KWKloeber]

I can rotate the belt 90 degrees on the longest run of the belt, and if anything might be a touch loose as it seems to deflect more than 1".  But there's no squealling and charging and exhaust water seem to be as expected.

Ok sounds good.
BTW that pump has nothing to do with the seawater system and exhaust - it is on a closed engine/water heater system.

Remove the belt and check for pump shaft wobble.  It might be worth rebuilding, but that's probably a toss up.

[Ron Hill]

PBY : The way I check the belt tension is take your fingers to the longest run and twist the belt. proper tension is when you can twist it ONLY 90 degrees (Old Farmers Almanac).

A thought

[KWKloeber]

Is this it? https://www.gciron.com/Kubota_Parts_16241_73037_PUMP_WATER_ASSY_p/ku-16241-73037.htm

Previously addressed:

-- there are two different Kubota pumps with different P/Ns
and impeller sizes.  Apparently, the pump capacity was insufficient and the impeller size was increased, which necessitated a whole string of changes at the front end of the engine.

Take your old pump to the dealer to match it up to be sure.[/b]

Or, at least remove the old pump and measure the impeller to match up the correct pump.

Messicks.com is a good online Kubota dealer with human type people you can talk to.  They supplied me most of the Kb parts manuals for the wiki.

Regarding the weep hole, it's defo rusted at and around the hole.  Major kudos for even noting that.
Can you clean off all the discoloration?  Perhaps watch it for a while. 

[pbyrne]

PBY : The way I check the belt tension is take your fingers to the longest run and twist the belt. proper tension is when you can twist it 90 degrees (Old Farmers Almanac).

A thought

Yup! That's been what I've been using as a rule of thumb.  The belt seems to 'vibrate' or deflect when the engine is running about an 1" maybe 1.5" when the engine is running, but it doesn't seem to be loose.

[pbyrne]

Is this it? https://www.gciron.com/Kubota_Parts_16241_73037_PUMP_WATER_ASSY_p/ku-16241-73037.htm

Previously addressed:

-- there are two different Kubota pumps with different P/Ns
and impeller sizes.  Apparently, the pump capacity was insufficient and the impeller size was increased, which necessitated a whole string of changes at the front end of the engine.
My guess is that Universals have the larger impeller. 
I am not 100% sure of the correct P/N for the B series engines but it is probably P/N #16241-73037 which is the newer P/N and probably the larger impeller. 
The older P/N is 16251-73032 and is probably the smaller impeller.

Take your old pump to the dealer to match it up to be sure.

Or, at least remove the old pump and measure the impeller to match up the correct pump.

Messicks.com is a good online Kubota dealer with human type people you can talk to.  They supplied me most of the Kb parts manuals for the wiki.

Regarding the weep hole, it's defo rusted at and around the hole.  Major kudos for even noting that.
Can you clean off all the discoloration?  Perhaps watch it for a while. 

Yeah taking it to the dealer makes the most sense.  Have to find something around Kingston Ontario.  Quick look didn't show anything.

I'll clean it off and see what happens.  I've never seen any liquid there at any time.  Is this something that would reasonably need replaced with 900ish hours?  This will sounds crazy but I think it even had the original Westerbeke belt on it until I changed it a couple of years ago.