Having gone to the trouble, I'd replace everything -- this little pump, the hose (absolutely essential!), the "sock" (a strainer or course filter), clamps, etc.
Sure, the pump is a tidy sum of bucks, but my time is also worth something and I'd rather spend it driving :-). Remember that testing it now will not reveal its future or remaining lifespan -- like the other responder wrote, sometimes the pump will work in this (dry run) mode despite worn brushes.