Water pump impeller blades scraping

[blue2000s]

Originally Posted by JFP in PA

The bits breaking off during cavitation create the scratches as they drag across the vane tips...............

Maybe...

See how it is discolored where the tab would be. Is that something you typically see?

[JFP in PA]

No, not really, it says the gasket was not correctly in place. But I have seen the same type of vane erosion (and worse) on pumps where the metal gasket was were it belonged and could not have been a factor in the vane wear.

The only way to know for sure if the gasket was a factor is to remove it, lay it on the old pump, and see if the gasket "finger" can reach far enough to have casued the wear, and the gasket itself should be beat to Hell as well.

[Steve Tinker]

I agree with JFP - in fact, the gasket "finger" would have worn away completely if it was in rubbing contact with the impeller vanes - one very thin sliver of steel causing all that damage to six seperate vanes seems extraordinary.

[Dale_K]

I think there is a certain amount of thrust load on the pump shaft when it's working in the car - think of a boat propeller. The water pump is sucking from the rear and tends to draw the impeller in towards the motor. Is there any fore/aft play in the shaft?