The impeller is fine. Drat!

BTW, I use silicone sealant.

"Thom Stewart" wrote

And now, the Raw Water Pump Impeller!
When you install the new impeller make sure that the side you put back
is just touching the impeller. This usually means a thin paper gasket.
Most of these pumps can't take a cork gasket, To much clearance creating
pump slippage and over heating.