Lexus 44050-48130 Brake Actuator Assembly

The Anti-lock Brake System (ABS) is designed to maintain vehicle steer ability, directional stability, and optimum deceleration under severe braking conditions and on most road surfaces. It does so by monitoring the rotational speed of each wheel and controlling the brake line pressure to prevent wheel lockup. The ABS system shares information with other optional systems, such as Electronic Brakeforce Distribution (EBO), Trac, and Vehicle Skid Control (VSC), to control vehicle handling. The actuator assembly, consisting of an electric hydraulic pump and solenoid valves, is responsible for providing hydraulic pressure and modulating brake line pressure. Speed sensors located at each wheel generate electrical pulsations indicating wheel rotational speed. The ABS computer processes information from the wheel speed sensors to control hydraulic line pressure and constantly monitors the system for faults. If a warning light comes on, preliminary checks can be performed, such as checking brake fluid level, verifying electrical connectors, checking fuses, and inspecting wiring connections. If the problem persists, the vehicle should be diagnosed and repaired by a qualified technician. Wheel speed sensors can be removed and installed by loosening lug nuts, raising the vehicle, disconnecting the electrical connector, removing the mounting bolt, and carefully pulling out the sensor. Installation is the reverse of the removal procedure.

The ABS shares information with other optional systems such as Electronic Brakeforce Distribution (EBO), Trac, and Vehicle Skid Control (VSC).