Avalanche 2500 2WD V8-8.1L VIN G (2002)
Brake Bleeding: Service and Repair
ABS Automated Bleed Procedure
W/JL4
ABS Automated Bleed Procedure (W/JL4)
Notice: When adding fluid to the brake master cylinder reservoir, use only Delco Supreme II, GM P/N 12377967 (Canadian P/N 992667), or
equivalent DOT-3 brake fluid from a clean, sealed brake fluid container. The use of any type of fluid other than the recommended type of brake fluid,
may cause contamination which could result in damage to the internal rubber seals and/or rubber linings of hydraulic brake system components.
Notice: Refer to Brake Fluid Effects on Paint and Electrical Components Notice in Service Precautions.
Important: This procedure is ONLY to be performed on vehicles equipped with option code JL4, Vehicle Stability Enhancement System (VSES).
Important: The base hydraulic brake system must be bled before performing this bleeding procedure. If you have not yet performed the base
hydraulic brake system bleeding procedure, refer to Hydraulic Brake System Bleeding before proceeding.
1. Install a scan tool.
2. Apply the park brake fully.
3. Start the engine and allow the engine to idle.
4. Depress the brake pedal firmly and maintain steady pressure on the pedal.
5. From the VSES Special Functions menu on the scan tool, select the Automated Bleed procedure.
6. Send the automated bleed command by pressing the On key on the scan tool.
After initiating the automated bleed procedure, the brake pedal will drop and then pulse back up, 8 times, while the LPA is being purged of any
trapped air.
7. Fill the brake master cylinder reservoir with Delco Supreme II, GM P/N 12377967 (Canadian P/N 992667), or equivalent DOT 3 brake fluid from
a clean, sealed brake fluid container. Ensure that the brake master cylinder reservoir remains at least half full during this bleeding procedure and
add fluid as needed to maintain the proper level. Clean the outside of the reservoir on and around the reservoir cap prior to removing the cap and
diaphragm, when cap removal is necessary.
8. Install a proper box-end wrench onto the RIGHT REAR wheel hydraulic circuit bleeder valve.
9. Install a transparent hose over the end of the bleeder valve.
10. Submerge the open end of the transparent hose into a transparent container partially filled with Delco Supreme II, GM P/N 12377967 (Canadian
P/N 992667), or equivalent DOT 3 brake fluid from a clean, sealed brake fluid container.
11. Have an assistant slowly depress the brake pedal and maintain pressure on the pedal.
12. Loosen the bleeder valve to purge air from the wheel hydraulic circuit.
13. Tighten the bleeder valve when full brake pedal travel has occurred.
14. Have the assistant slowly release the brake pedal. Wait 5 seconds before proceeding to the next step.
15. Repeat steps 11-14 until all air is purged from the same wheel hydraulic circuit.
16. After all air has been purged from the right rear hydraulic circuit and the bleeder valve is tightened securely, install a proper box-end wrench onto
the LEFT REAR wheel hydraulic circuit bleeder valve.
17. Repeat steps 9-15 at the left rear wheel hydraulic circuit.
18. After all air has been purged from the right rear hydraulic circuit and the bleeder valve is tightened securely, install a proper box-end wrench onto
the RIGHT FRONT wheel hydraulic circuit bleeder valve.
19. Repeat steps 9-15 at the right front wheel hydraulic circuit.
20. After all air has been purged from the right rear hydraulic circuit and the bleeder valve is tightened securely, install a proper box-end wrench onto
the LEFT FRONT wheel hydraulic circuit bleeder valve.
21. Repeat steps 9-15 at the left front wheel hydraulic circuit.
22. Fill the brake master cylinder reservoir to the maximum-fill level with Delco Supreme II, GM P/N 12377967 (Canadian P/N 992667), or
equivalent DOT 3 brake fluid from a clean, sealed brake fluid container.
23. Install a proper box-end wrench onto the LEFT FRONT wheel hydraulic circuit bleeder valve.
24. Install a transparent hose over the end of the bleeder valve.
25. Submerge the open end of the transparent hose into a transparent container partially filled with Delco Supreme II, GM P/N 12377967 (Canadian
P/N 992667), or equivalent DOT 3 brake fluid from a clean, sealed brake fluid container.
26. Use the procedure below to purge the Medium Pressure Accumulator (MPA) of any trapped air.
26.1.
With the engine still idling, select the Bleed MPA procedure from the VSES Special Functions menu.
26.2.
Send the bleed MPA command by pressing the On key on the scan tool.
26.3.
Open the LEFT FRONT wheel hydraulic circuit bleeder valve.
Important: Ensure that you fully release the brake pedal for at least 2 seconds between pedal strokes. The amount of accumulated time between
pedal strokes is calculated to deliver the most thorough bleed of the Medium Pressure Accumulator (MPA).
26.4.
Depress the brake pedal as far as possible using a smooth stroke.
26.5.
Release the brake pedal using a smooth stroke.
26.6.
Repeat steps 26.4-26.5 until 13 complete pedal strokes have been performed.
