Hydraulic Control Unit (HCU)

HCU consists of a pump motor assembly with built in motor sensor and valve block for controlling ABS. ABS control unit receives an output signal from motor sensor, which detects condition of pump motor, HCU controls brake fluid pressure to each caliper using solenoid controlled valves to modulate pressure to any one wheel, preventing wheel lock-up. HCU is controlled by ABS control unit. Each caliper has 2 solenoid controlled valves, one controlling input of fluid to a caliper and one controlling fluid output of fluid from a caliper. These solenoids are operated only when wheel lock-up is about to or is occurring.