What is the best way to flush out old brown brake fluid. I am rebuiling the brakes on my 69 Camaro and want to start out with fresh new fluid. Also, any opinions on silicone fluid?

I can tell you what I found out on this site (do a search on brake fluid) that : silicone is BAD and synthetic is GOOD.
You could probably use a vaccum bleeder to pull out the old and pull in the new. You could do a search on this issue also. There is an amazing amount of info on this site.
Good luck,
Guy

Suck out all the fluid you can from the master cyl. wipe it clean and refill with fresh fluid and bleed the system until clean fluid comes out of the wheel cyls.

Some like silicone fluid and some don't. I don't like it but I like to race and drive my cars hard. I've seen a couple of friends have brake system problems with it.
David

If it's time for brake work, consider replacing or rebuilding the calipers / cylinders. Purge the lines as David recommended. The reason I recommend the caliper / cylinder work is that a lot of rusty cruddy muck will collect there.

-dnult