Chrysler Full-Size Vans 1989-1998 Repair Guide

General Information


The RWAL brake system uses a standard master cylinder and booster arrangement with a split hydraulic circuit. An electronic control module, rear wheel speed sensor and a hydraulic pressure valve are the major components of the system.

There are some minor changes in brake lines, hoses and electrical circuits to accommodate RWAL on models so equipped. No hydraulic pumps are used; brake pressure comes directly from the pedal application. The system provides stability by allowing at least one rear wheel to remain unlocked. It's still possible to lock the front wheels, since this system works on the rear wheels only.

An amber Anti-Lock warning light is installed on the instrument panel along with the standard red brake warning lights. Looking for this amber warning light is the quickest way of determining whether or not the vehicle is equipped with RWAL.

A speed sensor is mounted to the top of the rear differential housing. A toothed exciter ring is press fit onto the differential case next to the differential ring gear and provides the signal for the sensor.

The electronic control module is located on the lower right side cowl panel. The control module monitors the rear wheel speed and controls the dual solenoid valve. The module also performs a system self-check every time the ignition switch is turned from the OFF to the ON position.

The hydraulic pressure valve allows brake fluid to flow freely between the master cylinder and the rear brakes under normal operating conditions. Once anti-lock braking begins, the control module triggers the valve to either isolate or reduce pressure to the rear wheels.