[jaykay]

Is everyone vacum bleeding their cooling systems after pump changes? Without vacum system bleeding you can spend a whole day burping the system ...and you are never really sure that you have managed get rid of all air bubbles. Air in the system would be a potential cavitation mechanism. If this cavitation occurs near the impeller blades of the pump it can cause failure of the blade. Cavitation can cause failures of impellers even if they are metal.

It is my guess that cyclic stresses from pump cavitation are giving rise to pump impeller blade failures. In addition to this you have age related weakening of the composite material as noted by J. Raby at flat six

If pump your has failed you may be eligible for a free replacement as far I have heard. I only see evidence of seepage on mine so this won't be enough to get a free one. I have an OEM one ready to go in, hopefully it won't let me down....oh yes make sure you change the coolant tank res. cap