Rusty 2YM15 sea water pump

[dee.yeah]

Last week I replaced the cracked sea water filter and the hose of the 3-year-old 2YM15 on my Y25.

I noticed the sea water pump is pretty rusty with quite some greenish stuff on it. Is it normal? Or it's a sign of some problem?

Thx!

 

[Boffin]

the water pump is made by brass, the greenish is the copper oxided due to reaction with the sea water . There may be some leaking in the joint , othe wise it should be clean .

 

[jnovie]

If the pump is leaking you will generally see evidence of residue directly beneath the pump on the sump itself. Be certain to service the pump by changing the impeller and gasket on a regular basis as recommended in the Yanmar manual. Keep the sump beneath the engine very clean and dry so that you can spot problems such as leaks quickly.

 

[dee.yeah]

Thanks for the advices. It seems the pump is not leaking, as there is not significant residue underneath. But the old hose was aged, and I guess it leaked a bit. Anyway I've replaced it.

The engine compartment hasn't been dry until recently I fixed the leaking muffler and filled the unused via-hull hole.

 

[jnovie]

I recently had a water pump related issue.
I started my engine and checked to see if water was flowing out of the exhaust. Alas no water. Shut down the engine immediately. Checked to see if the sea cock was open and it was. Checked the impeller and found that the center bronze axel had separated from the rubber portion of the impeller. In other words the axel was spinning but the rubber portion was not which accounted for the lack of cool sea water being pumped thru the engine cooling system. I had last changed the impeller about a year ago. I am going to change my impeller every six months from now on. Replacing an impeller while underway is not an easy task particularly if the sea conditions are rough. Best to do so at the dock as a regular engine maintenance task.

 

[furdui]

A bush(as in shrub,as in opposed to city)solution

because you just said it is hard to replace the impeller while on the way,here is what I did,about FIVE years ago!!!,on a new impeller I pulled out the pin by drilling the rubber and replaced the pin with a bolt,same size,shaped two flat washers to sit properly between the wings,pass the bolt throu washers,brass bush,a spring washer and tighten with a nut making sure the bolt does not extend beyond the nut.
I did the same to the old impeller and keep it as spare.
It is true,I do more sailing then motoring,but it is 5 years since and still going,and before I used to replace the impeller almost every year!!

attached is a sketch how I've done it

I recently had a water pump related issue.
I started my engine and checked to see if water was flowing out of the exhaust. Alas no water. Shut down the engine immediately. Checked to see if the sea cock was open and it was. Checked the impeller and found that the center bronze axel had separated from the rubber portion of the impeller. In other words the axel was spinning but the rubber portion was not which accounted for the lack of cool sea water being pumped thru the engine cooling system. I had last changed the impeller about a year ago. I am going to change my impeller every six months from now on. Replacing an impeller while underway is not an easy task particularly if the sea conditions are rough. Best to do so at the dock as a regular engine maintenance task.

 

[jnovie]

because you just said it is hard to replace the impeller while on the way,here is what I did,about FIVE years ago!!!,on a new impeller I pulled out the pin by drilling the rubber and replaced the pin with a bolt,same size,shaped two flat washers to sit properly between the wings,pass the bolt throu washers,brass bush,a spring washer and tighten with a nut making sure the bolt does not extend beyond the nut.
I did the same to the old impeller and keep it as spare.
It is true,I do more sailing then motoring,but it is 5 years since and still going,and before I used to replace the impeller almost every year!!

attached is a sketch how I've done it

Thanks for your reply and "thumbnail sketch". Your solution is "ingenious" as it keeps the bushing from breaking free of the rubber impeller.