have seen it come off drift car with bent shaft :werd:
driver said it felt funny [no rebound or bump will do that]
have only seen this happen in accidents
you get what you PAY for :burnout:
cheak calipers for signs of leakage
if the seals in the master cylinder are stuffed it wont hold pressure [foot will slowley go to the floor]
but if you are having to top it up it has to be leaking
good luck