GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2002 🢒 Yukon - 2WD 🢒 Brakes 🢒 Hydraulic Brakes 🢒 Antilock Brake System Automated Bleed Procedure

Antilock Brake System Automated Bleed Procedure w/JL4

Notice: When adding fluid to the brake master cylinder reservoir, use only Delco Supreme 11®, 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: Avoid spilling brake fluid onto painted surfaces, electrical connections, wiring, or cables. Brake fluid will damage painted surfaces and cause corrosion to electrical components. If any brake fluid comes in contact with painted surfaces, immediately flush the area with water. If any brake fluid comes in contact with electrical connections, wiring, or cables, use a clean shop cloth to wipe away the fluid.

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 in Hydraulic Brakes 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.

    7. 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 11®, 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.

    8. 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 11® , 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 11® , 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 11®, 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.
    27. 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.

            Important: Observe the MPA switch parameter as the pedal strokes are being performed. The MPA switch parameter should change from Uncharged to Charged several times during the first 8 or 9 strokes. After approximately 10 pedal strokes, the MPA switch parameter should remain Charged. If the parameter does not change, repeat all of step 26.

    26.6. The valves within the BPMV are active for the first 13 complete pedal strokes to enable the MPA to be filled and discharged, forcing any trapped air out of the LEFT FRONT wheel hydraulic circuit bleeder valve.
    26.7. Continue to depress and release the brake pedal while observing the fluid within the transparent hose. When no air is observed exiting the hydraulic system, proceed to the next step.
    26.8. Depress the brake pedal and maintain pedal position.
    26.9. Have an assistant tighten the bleeder valve.
    26.10. Release the brake pedal.
  27. Remove the scan tool from the vehicle.
  28. Fill the brake master cylinder reservoir to the maximum-fill level with Delco Supreme 11® , GM P/N 12377967 (Canadian P/N 992667), or equivalent DOT 3 brake fluid from a clean, sealed brake fluid container.
  29. Slowly depress and release the brake pedal. Observe the feel of the brake pedal.
  30. If the brake pedal feels spongy, repeat this entire bleed procedure. If the brake pedal still feels spongy after repeating this procedure, inspect the brake system for external leaks. Refer to Brake System External Leak Inspection in Hydraulic Brakes.
  31. Observe the brake warning indicator to determine whether or not the indicator remains illuminated.
  32. If the brake system warning lamp remains illuminated, DO NOT allow the vehicle to be driven until it is diagnosed and repaired. Refer to Symptoms - Hydraulic Brakes in Hydraulic Brakes.

Antilock Brake System Automated Bleed Procedure Without JL4

Notice: When adding fluid to the brake master cylinder reservoir, use only Delco Supreme 11®, 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: Avoid spilling brake fluid onto painted surfaces, electrical connections, wiring, or cables. Brake fluid will damage painted surfaces and cause corrosion to electrical components. If any brake fluid comes in contact with painted surfaces, immediately flush the area with water. If any brake fluid comes in contact with electrical connections, wiring, or cables, use a clean shop cloth to wipe away the fluid.

Important: This procedure may be performed on all vehicles EXCEPT those equipped with option code JL4, Vehicle Stability Enhancement System (VSES).

Important: The base hydraulic brake system must be bled before performing this automated 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 to the vehicle.
  2. Start the engine and allow the engine to idle.
  3. Depress the brake pedal firmly and maintain steady pressure on the pedal.
  4. Using the scan tool, begin the automated bleed procedure.
  5. Follow the instructions on the scan tool to complete the automated bleed procedure. Release the brake pedal between each test sequence.
  6. Turn the ignition OFF.
  7. Remove the scan tool from the vehicle.
  8. Fill the brake master cylinder reservoir to the maximum-fill level with Delco Supreme 11®, GM P/N 12377967 (Canadian P/N 992667), or equivalent DOT-3 brake fluid from a clean, sealed brake fluid container.
  9. Bleed the hydraulic brake system. Refer to Hydraulic Brake System Bleeding .
  10. With the ignition OFF, apply the brakes 3-5 times, or until the brake pedal becomes firm, in order to deplete the brake booster power reserve.
  11. Slowly depress and release the brake pedal. Observe the feel of the brake pedal.
  12. If the brake pedal feels spongy, repeat the automated bleeding procedure. If the brake pedal still feels spongy after repeating the automated bleeding procedure inspect the brake system for external leaks. Refer to Brake System External Leak Inspection .
  13. Turn the ignition key ON, with the engine OFF; check to see if the brake system warning lamp remains illuminated.
  14. If the brake system warning lamp remains illuminated, DO NOT allow the vehicle to be driven until it is diagnosed and repaired. Refer to Symptoms - Hydraulic Brakes .
  15. Drive the vehicle to exceed 13 km/h (8 mph) to allow ABS initialization to occur. Observe brake pedal feel.
  16. If the brake pedal feels spongy, repeat the automated bleeding procedure until a firm brake pedal is obtained.