Chris,
You need a new pump. Pointless putting that heap of junk back on.
Get a pump with an impeller that looks like this...
Cast impeller.
The pressed steel impellers like the one you have do not pump as efficiently and cause cavitation when working hard, plus the blades rust reducing pumping efficiency.
This x 100000000. Never put a pressed sheet metal impeller on anything.
Don't hesitate to call me if you have any questions or need any parts haha