I figure to change the impeller every other season, unless I'm in a lot of muddy water or suck some muck.<br /><br />The whole pump? I won't change that until it shows some sort of damage. But that's just me.
its just to easy to purchase the entire kit and be done with it. comes with all nessasary gaskets and rubber parts as well as housings, wear plates and cups. its maybe 20 dollars more than buying the parts seperatly.