07 Impala Windshield Washers

This is a simple but irritating thing. The windshield washers ran out of fluid. After refilling the tank, they will not prime. After several weeks of periodically trying them, nothing. There was absolutely no issue before this. I've never had this problem before, even on a 64 impala and 67 chevelle. I suppose some dirt might have gotten in there but I find that highly unlikely. Is there a manual priming method for these?

Bum. I'm having the same problem.