Ever replace your generator impeller while it was still hot?

[Cosmo Knot]

Was on the hook over Labor Day weekend and the generator stopped.

Opened the impeller cover and half of the blades were missing. So I got out my spare and started the replacement process.

It took me two hours to get the old impeller out. Access is tough on my 390 MY, but I had done it before on a cold generator and didn't have an issue getting the old one out.

I assume that it was that the impeller was still hot and I couldn't get a grip on the rubber. I would just pull a chunk of it out and the impeller would move little, if at all. Finally got a drywall screw into the base and slowly pulled it out (after several attempts that just pulled the screw loose).

I still have the old impeller with the screw in it, and it is SOLIDLY in the (now cold) rubber.

Just wondering if anyone else had the same experience.

Yes, I could have waited for it to cool, but then it would be midnight or the next morning, and I wanted to get it done.

Was hoping for a couple seasons on the impeller. I guess this will be an annual replacement item from now on.

 

[hottoddie]

Hope you found and removed the broken impeller blades from the heat exchanger.

 

[alnav]

I've never tried to change a hot impeller, but I find it's easier to just remove the whole water pump, change the impeller, then reinstall the pump. I suppose if you had done that you could have cooled the pump and perhaps avoided the stuck impeller.

 

[Stee6043]

Just for the sake of discussion...the impeller/raw water pump should not be hot under normal operating conditions. I imagine the OP's pump was hot because of the failed impeller bits and pieces binding and creating friction inside the pump housing. Or perhaps a failing bearing in the pump/hub (which could be why the impeller only lasted a year??)?

If you replace your impeller before it fails it should be sea water temp immediately after shutdown. Maybe a few degrees warmer due to heat soak from the motor? But surely it should not be "hot".

 

[Cosmo Knot]

If you replace your impeller before it fails it should be sea water temp immediately after shutdown. Maybe a few degrees warmer due to heat soak from the motor? But surely it should not be "hot".

Poor choice of words on my part. Not hot, but normal operating temperature. I don't know what the RPM of the pump is, but the rotational friction is going to heat it up to above the raw water temp.

And yes, I fished the broken parts out before I started up again.