Abs Brake System Maintenance

The anti-lock brake system provides the ability to steer around objects while braking in slippery road conditions. When the system senses a wheel is about to lock up, the brake pressure is released from that wheel to help maintain directional control. The system requires little service and maintenance, but brake fluid replacement is still needed. Over time, the anti-corrosion properties of the brake fluid that protect delicate parts dissipate, and the fluid becomes slightly thicker. Routine fluid replacement restores the fluid to factory specs.

Fluid Maintanence

Fluid replacement involves removing old fluid from the system and bleeding the brakes in the proper sequence. Most ABS systems do not require any special functions to bleed the system. However, certain systems, like the Delco ABS IV, do. A scan tool must be used to home the motor pack on this system before bleeding to remove the fluid that is in the ABS systemssystem. Most others home the solenoid valves a few seconds after the key is turned on. To replace the fluid, turn the key on and wait for the ABS warning light to go off and bleed according to sequence, as you would normally do during servicing of the standard brake system.

Wheel Speed Sensor Maintanence

Check the wheel-bearing play as you would in a routine brake inspection. The gap between the exciter ring in the hub assembly and the wheel speed sensor is critical, and loose wheel bearings will cause inaccurate wheel speed signals to the ABS computer. Another area of routine maintenance is the wheel speed sensor. As the brake pads wear, the magnet in the wheel speed sensor will attract metal particles. These particles can coat the sensor tip and dampen the signal causing inaccurate readings. This is especially a concern if the brake pads have worn to the point that metal-to-metal contact has occurred. Remove the sensor from the hub assembly and remove these particles. Many times this will fix an ABS malfunction.