I could not find this information anywhere, so I have put a notated image together to identify and show which brake pipe goes where on the Mercedes Vito W639. The notation of pipe locations will be carried across all ranges including Sprinter although the pump/controller module may differ slightly in design. The main ABS pump/controller body is stamped with markings next to each hydraulic port, you will find below the identification of these and where the connected pipes are routed.
Great info thanks for posting!
Some day my brakes will need the fluid replaced.