Anti-Lock Brake System: Description
The Kelsey-Hayes 4-Wheel Anti-Lock (4WAL) brake system is used to prevent wheel lock-up during heavy braking. This allows driver to maintain steering control while stopping vehicle in shortest distance possible. The system consists of Electro-Hydraulic Control Unit (EHCU), Vehicle Speed Sensor (VSS), VSS buffer, wheel sensors, warning lights, electrical wiring and hydraulic lines. See Fig 1.
The EHCU consists of the BPMV, Electronic Brake Control Module (EBCM), and combination valve. The BPMV consists of internal control cartridges, electric motor and pumps. Components of the EHCU are individually replaceable.