[tomp]

You dont need to flush the system, although it is a good idea. What I do is use the same hand pump I use for adding fluids to my diffs and syphon the old brake fluid out. This keeps you from having to bleed the brakes.

Each time you apply the brakes, it pushes some new fluid in and some old fluid comes to the top. Eventually, all of the old fluid down the lines gets diluted with the new fluid. I do this everytime the fluid gets dark. It does improve the feel of the brakes and brake fluid is only intended to last about a year with normal driving