Aside from what the others have said, I find it helpful to prefill the intake hose with water to the pump before starting. This primes the pump and gets the requisite coolant flowing (water) to take heat away from the impeller blades. If you don't do this it can take many seconds to suck water up and prime the pump particularly if the suction side is not 100% air tight. This takes mucho life off the impeller.

BT

I found myself still replacing my Globe impeller every season just for the satisfaction of it being new and not an old one in there. Although I have to say It looked GREAT when replacing But I just wanted cheap insurance out on the water. But that doesn't prevent picking up crap on any given day in dirty water

Here are two pics of a 25 hour Globe Blue.

i need a key for the blue impellers help

Trenton Marine in Nj stocks them

thank you

http://trentonmarine.com/parts.htm