If the breaker keeps blowing, either the breaker is bad like you said or there's a short in the wiring somewhere.
If you can trace the wires you can see, check for damage causing a short.
COnsidering the breaker is easy to replace and not very expensive, I'd try that second. If that doesn't work then considering there are parts of the wire you can't see, just use the old wire to pull some new wire from the pump to the panel. likely a damaged spot.
'06 X2 MCX
"I understand why some people may not want to do this the way I have recommended but I can't understand the death grip some people have on a toilet plunger with a hose fitting." -JimN