Automated Bleed Procedure

Perform the automated ABS bleed procedure whenever one of the following conditions occurs:

• Manual bleeding at the wheel cylinders does not achieve the desired pedal height or feel.
• You replace the Brake Pressure Modulator Valve (BPMV).
• Extreme loss of brake fluid has occurred.
• Air ingestion is suspected.

If none of the above conditions applies, use standard bleed procedures. Refer to Hydraulic Brake System Bleeding (Manual) or Hydraulic Brake System Bleeding (Pressure) in Hydraulic Brakes.

This procedure uses a scan tool in order to cycle the system solenoid valves and to run the pump motor in order to purge the air from the secondary circuits. These secondary circuits are normally closed, and are only opened during system initialization at vehicle start up and during ABS operation. The automated bleed procedure opens these secondary circuits and allows any air trapped inside the BPMV to flow out toward the wheel cylinders or the calipers where the air can be purged out of the system.