Brake Valve Cycling
Brake Valve CyclingWarning
Brake fluid may irritate eyes and skin. In case of contact, take the following actions:
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Eye contact-rinse thoroughly with water.
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Skin contact-wash with soap and water.
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If ingested-consult a physician immediately.
Warning
: During the Brake Valve Cycling procedure, battery shortage may occur. It is recommended you connect secondary power supply to battery for battery shortage prevention.
1. Connect required brake bleeding equipment.
2. Raise and support vehicle. Refer to Lifting and Jacking the Vehicle in SI.
3. Remove all tire and wheel assemblies. Refer to Tire and Wheel Removal and Installation in SI.
4. Drain brake fluid from the brake system.
Note
Fill the master cylinder reservoir with brake fluid. Keep the master cylinder at least 1/2 full of fluid during the brake bleeding operation. Fill brake system with Delco Supreme 11 Brake Fluid (P/N 19299818 USA, P/N 19299819 Canada).
5. Bleed the brake system. (DO NOT perform air bleeding through scan tool). Refer to Hydraulic Brake System Bleeding in SI.
6. Connect scan tool.
7. Select "F2.Special Functions" and then Select "F2.Brake Valve Cycling".
8. Start brake valve cycling.
This screen displays with the Tech 2 is starting to communicate with the vehicle.
9. Waiting for data.
10. The "Procedure in Progress" message will appear from the Brake Valve Cycling screen.
11. The "Apply and Hold Brake Pedal" message will appear from the Brake Valve Cycling screen.
The auto brake valve cycling process will run for 25 seconds. A little pedal down/up will occur during the process.
12. The "Procedure in Progress" message will appear from the Brake Valve Cycling screen.
Note
Perform base brake bleed for ONLY the front wheel circuits after each loop has been completed. Open each front caliper bleeder valve 1 time for 1-2 seconds and then close it. This will only extract a very small quantity of brake fluid from each front caliper. Then proceed to the next loop or count. Repeat steps 11-13 until the 10th loop has been counted. The procedure is automatic; the procedure will only complete 10 loops and then stop.
13. The "Release Brake Pedal" message will appear from the Brake Valve Cycling screen.
14. The "Procedure Complete" message will appear on the Brake Valve Cycling screen.
15. To ensure the brake system is functioning properly, perform the ABS Module Inspection procedure again. Refer to ABS Module Inspection in this bulletin.