Thanks for the comments, especially the warning about spraying brake fluid due to pressure. I'll probably cover the master cylinder with a towel to prevent damage to exterior paint.

I think the only reason not to change fluid along with the rotor and pad would be if the fluid had been changed in the past few months. The non silicone brake fluid is touted to 'suck' moisture out of the air so quickly that it should be changed at least about every two years. It is this corrosive moisture in the fluid that makes me want to flush the ABS unit.

About 58 years ago I started using the pump & bleed method, worked ok but required two people. Then I discovered gravity bleed ( just open all caliper bleeders ) & keep topping up the reservoir with new fluid until they all run clear. That has sufficed in keeping clean fluid in the master cylinder & brake calipers. I'm now more concerned about the ABS mechanism that supposedly can be flushed with a pressure flusher like the Motive. I also like the idea of having pressure on the fluid ( maybe a pressure flow will clean sediment better than gravity flow ).

Any opinions on how to flush ABS mechanism? I'm guessing I've lucked out in the past & never have had any ABS failures due to old fluid. I would like to flush the ABS if the pressure type method will do so or any other method that I can do myself.