That article is good. I am not sure about the bit where it says when the ABS activates there is circulation in the circuit. That cannot possibly be correct for the fluid in the hoses and the calipers - it just does not make sense. There is no device I can think of that will circulate fluid when one end of the system is completely closed. You can not push the fluid further and you cannot draw it up.

Unless, unless, unless: on systems with ABS there are return hoses from the calipers. I have not observed any such return hoses on any cars I have serviced. Has anyone else?

Also, as the article says the ABS has valves etc that need to be activated in order to facilitate the fluid change. We at home, how are we going to do this? I plan to change fluids tomorrow, any help appreciated