Quote from Terry Haines on this subject covered earlier this year in a prior post:
"The 'cone is the s/steel insert in the back half of the pump housing..it matches the angle of the pump vanes and allows a minimal clearence between itself and the impeller, the hole in the center controls the amount of draw/volume the pump can move at a given speed...if the cone is not in place the 'assembly' is no longer a pump....
From everything I've read and heard, pump failures have been somewhat of a mix between cones coming loose and bashing the plastic impeller to pieces (double-whammy there) and the plastic impeller simply disentigrating for as yet unknown reasons (some say earlier impellers were made of substandard materials), with the cone still in place.
I'll be doing my pump here in the next week or two, so I'm definitely checking to see if the cone insert is loose or not.
For more info, do a search on "water pump failure" or any variation of such. You'll find plenty of reading material...
