Hydraulic System
Hydraulic system consists of master cylinder, delivery lines, hydraulic modulator, electric solenoid valves, return delivery pump and brake calipers. Solenoid valves are contained within hydraulic modulator. Individual solenoid valves are used for pressure control to left and right front calipers, while rear brake line pressure is controlled by a common, regulated rear solenoid valve.
Hydraulic modulator can control hydraulic pressure to each front brake caliper or both rear calipers independently of pressure produced by brake master cylinder. However, a higher pressure than that of brake master cylinder is not possible.
If lock-up conditions occur, ECU sends a signal to hydraulic modulator and an electric return delivery pump reduces hydraulic pressure by pumping brake fluid from brake caliper(s) to master cylinder. This procedure is repeated at either front or both rear calipers until lock-up condition is eliminated.
The hydraulic modulator, solenoids, relays and return delivery pump are contained in a single assembly located under a cover in spare wheel well area.