Brake fluid replacement ?

[NiXBoX]

I am following the 101 project guide for Boxster and am planning on replacing the brake fluid.

The reservoir currently contains the old brake fluid. Should I extract the old fluid from the reservoir first via suction pump and then fill it with new brake fluid and then proceed with the bleeding process per the guide?

I am concerned that if the reservoir is filled with the old fluid and I am replacing it with the new fluid using the power brake bleeder that the new fluid will just mix with the old and I don't have pure fluid replacement.

Appreciate the suggestions.

[JFP in PA]

If you use a pressure bleeder like the Motive unit, you would be wasting your time emptying the reservoir before bleeding the brakes; the system simply pushes ALL the old fluid out ahead of the fresh fluid.

[Carlton Bale]

The old and new fluid will mix a little bit in the reservoir bleeding the brakes. It’s not enough to worry about because the volume of the reservoir is cycled several times over. That said, brake fluid is relatively inexpensive and it bottles can’t be stored long once opened (due to moisture absorption), so there is no downside to suctioning out the old fluid first and using the entire bottle of brake fluid for the service. For what it’s worth, that’s what I do, even though it’s probably not necessary. A turkey baster works well.

Also, I installed SpeedBleeders on all of the calipers to further reduce the chance of air getting back into the system. Again, not necessary, but doesn’t hurt.