I agree with Jeff's reply.  I've never changed the brake fluid except when
having a brake job, which is usually at around 80,000 miles (alot of
freeway driving).  However, I will start to do this as preventative
maintenance on my new car.  Also, there are brake system flushing agents
that can be used but the problem is that if any of the agent is left in the
system, it can cause problems, so it's been recommended NOT to use them unless
you are 100% certain that you can remove all of the flushing agent.  Just for
your info, I was quoted a price of: labor=$29.95 and fluid=$9.95 for
flushing the brake system; this in conjunction with a break job so I don't
know if it was more without the brake job. This is in the S.F Bay Area.
