When your rack starts to go. It will feel notchy when turning the steering wheel when cold. As it warms up, the feeling will go away.This is the fluid bypassing the seals inside the rack. as it warms up. The clearances will tighten up around the seals. Stopping the bypassing. This is one of the first signs of a bad rack.
Rubber o-rings and seal don't like brake fluid. They will get soft, and fall apart.
For the amount you said you put in. A good flush should take care of it.
