Changing the fluid every 30,000 miles or so is the best thing you can do.
In a car that has had this service neglected for a long time, it's possible
that the damage is already done... changing the fluid might even speed the
death.

>
> Will it help prevent this builddup if we push the pedal all the way to
> the floor (maybe by opening one bleed valve) a few times every few
> thousand miles?