Info - Service Procedure Guideline for Low Brake Pedal/Air in System Conditions

This bulletin is being revised to update the title line with the word "brake". Please discard Corporate Bulletin Number 03-05-25-009 (Section 05 - Brakes).

Important: Please refer to the following information before replacing or reprogramming any brake components.

This bulletin is being issued to emphasize the importance of following the proper repair instructions in order to eliminate unnecessary part replacements and comeback repairs.

If low brake pedal height or air in the brake system occurs to the above listed vehicles, the following service procedure guideline should be performed.

Important: In order to achieve the proper results, the required tools and recommended procedures must be used.

Tools Required

Important: Do NOT use vacuum sources at the bleeders when performing the following procedures. Use of vacuum during the bleed procedures will not remove all of the air from the brake system.

1. Perform a pressure bleed of the base brake system. Refer to Hydraulic Brake System Bleeding Pressure in the Hydraulic Brakes sub-section of the Service Manual or SI document #1352111 for CTS, #741839 for SRX.
2. Perform the Anti-Lock Brake System (ABS) Automated Bleed Procedure. Refer to Anti-Lock Brakes sub-section of the Service Manual or SI document #1406176 for CTS, #1405256 for SRX. During this procedure, whenever applicable, refer to the Hydraulic Brake System Bleeding PRESSURE procedure.
3. If, for any reason, it becomes necessary to perform a brake pedal position relearn calibration, refer to Brake Pedal Position Sensor Calibration Description and Operation, located in the Lighting Systems sub-section of the Service Manual. In SI, refer to document #1207189 for both CTS and SRX. Ensure the scan tool is updated with software version 23.006 or greater.

The ABS Automated Bleed Procedure uses a scan tool to cycle the system solenoid valves and run the pump in order to purge any air from the secondary circuits. These 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 in these circuits to flow out toward the brake corners.