Operation - Hydraulic Circuits And Valves: Notes
NOTE:
The following applies for both MK25 and MK25e ABS.
The hydraulic fluid control valves within the HCU control the flow of pressurized brake fluid to the wheel brakes during the different modes of ABS braking and traction control. The following paragraphs explain how this works. For purposes of explanation only, the following diagrams show only one hydraulic circuit, the Right Front wheel braking circuit.