Thanks, Benzmac. I looked carefully at the E430, but I can't find a bleed port on the pump unit. At this point, I am going to assume that I am performing an effective flush by pressure bleeding the system at the calipers. I flushed about 500ml through each caliper. I didn't have any problem with the pump energizing and pressurizing the calipers while I bled the system. I did have the ignition off, but without any wiring diagram I don't know if that shuts down power to the pump. If you have any other hints please forward them.