Water pump damage

[oldman]

Not sure how well the photo shows it but this is the water pump impeller from the 89 bike. No additive in coolant and waterways pretty grotty, shaft is pitted and bearing surface more or less destroyed, another part to order. Always use additive!

[Calum]

How tight do the tolerances need to be I wonder?

[ricky0115]

Damn I always mix my coolant with distilled water, is that what you mean by additive?

[Calum]

@ricky0115 Rust inhibitor

[oldman]

I have a new pump seal to go on but don't think it will last long with that shaft (if at all) , ordered replacement, there is a polished surface on the shaft that's destroyed, very little left.,don't know if it is a coating but tried polishing rough surface down but no good. Not willing to risk a leak.

[declan]

@oldman that’s one part that really is a bitch to repair seems like anything to do with the water pump is best to get the parts as you are

[Calum]

It's not the end of the world, the pitting can be welded up then reground out, probably cheaper to buy a new impeller.

Or you could turn the impeller down on a lathe and create a press fit shim onto the shaft.

You know, in the event the part is discontinued...

[declan]

@calum isn’t the thought of all parts discontinued terrifying