K75s Water/Oil pump shaft condition

[nortagem]

I'm in the process of getting a 1990 K75s on the road again and recently discovered coolant dripping from the weep hole. I pulled off the water/oil pump and will be replacing all the seals and impeller, but wondering if the impeller drive shaft needs to be replaced.

Compared to other examples I've seen, the corrosion/pitting isn't terrible, but there's still a band that's about 2mm wide where you can feel it's rough. Not sure what the tolerance is for it to affect the ability to get a good seal.

Because it's already taken apart, I'd normally lean towards replacing it, but the replacement from Euro Motoelectrics (https://www.euromotoelectrics.com/product-p/pumpgear793.htm) is out of stock and it sounds like new stock might be 4-8 weeks out.

Is this level of pitting acceptable to re-use the original shaft, or is it better to just wait a month or two and install a new one?

[sooprvylyn]

Mine was about that bad when I did mine.  I just cleaned it up well with a stainless steel wire wheel, lightly sanded it to remove any of the higher rough spots that might effect new seals, and did the new seals.  It hasnt had any issues since october.  I think you are good to reuse it if you clean it up. 

Def dont use a normal wire wheel on it, because you'll impregnate it with mild steel causing surface rust that might cause you problems. Only use stainless wheels on stainless parts.  Also dont use your stainless wheels on mild steel parts because then you contaminate the wire wheel and cant use it later on stainless parts.

Worse case is that you redo it again if it craps out, but as you can see, its very accessible, and you'll already have the tools.  Those impeller drive shafts arent cheap.