Cruze

Hydraulic Brake System Bleeding

Warning: Refer to Brake Fluid Irritant Warning in the Preface section.

Caution: Refer to Brake Fluid Effects on Paint and Electrical Components Caution in the Preface section.

Caution: When adding fluid to the brake fluid reservoir or to the clutch fluid reservoir, use only DOT-4+ brake fluid from a clean, sealed container. This polyglycol brake fluid is hygroscopic and absorbs moisture. Do not use fluid from an open container that may be contaminated with water. Improper or contaminated fluid could result in damage to the system components.

Use GM recommended brake fluid, or equivalent DOT-4+ brake fluid. Refer to Adhesives, Fluids, Lubricants, and Sealers .

1. Place a clean shop cloth beneath the brake master cylinder to prevent brake fluid spills.
2. With the ignition OFF and the brakes cool, apply the brakes 3–5 times, or until the brake pedal effort increases significantly, in order to deplete the brake booster power reserve.
3. If you have performed a brake master cylinder bench bleeding on this vehicle, or if you disconnected the brake pipes from the master cylinder, or disconnected the brake pipes from the proportioning valve assembly or the brake modulator assembly, you must perform the following steps to bleed air at the ports of the hydraulic component:

Note:  If removal of the reservoir cap and diaphragm is necessary, clean the outside of the reservoir on and around the cap prior to removal.

3.1.	Ensure that the brake master cylinder reservoir is full to the maximum-fill level. If necessary, add NEW brake fluid from a clean, sealed brake fluid container. Refer to Adhesives, Fluids, Lubricants, and Sealers .

Note: For the brake pressure modulator valve, perform these steps in the sequence of system flow. Begin with the fluid feed pipes from the master cylinder.

3.2.	With the brake pipes installed securely to the master cylinder, brake pressure modulator valve, loosen and separate one of the brake pipes from the port of the component.

3.3.	Allow a small amount of brake fluid to gravity bleed from the open port of the component.

3.4.	Reconnect the brake pipe to the component port and tighten securely.

3.5.	Have an assistant slowly depress the brake pedal fully and maintain steady pressure on the pedal.

3.6.	Loosen the same brake pipe to purge air from the open port of the component.

3.7.	Tighten the brake pipe, then have the assistant slowly release the brake pedal.

3.8.	Wait 15 seconds, then repeat steps 3.3–3.7 until all air is purged from the same port of the master cylinder.

3.9.

With the front brake pipe installed securely to the master cylinder, proportioning valve assembly, or brake modulator assembly, after all air has been purged from the first port of the component that was bled, loosen and separate the next brake pipe from the component, then repeat steps 3.3–3.8 until each of the ports on the component have been bled.

3.10.

After completing the final component port bleeding procedure, ensure that each of the brake pipe-to-component fittings are properly tightened.

Note: Clean the outside of the reservoir on and around the reservoir cap prior to removing the cap and diaphragm.

4. Fill the brake master cylinder reservoir to the maximum-fill level with brake fluid from a clean, sealed brake fluid container. Refer to Adhesives, Fluids, Lubricants, and Sealers .
5. Remove the brake master cylinder reservoir cap.



6. Install a customary brake bleeder adapter (1) to the brake master cylinder reservoir.
7. Check the brake fluid level in the customary brake pressure bleeder (2). Fill NEW brake fluid from a clean, sealed brake fluid container as necessary to bring the level to approximately the half-full point. Refer to Adhesives, Fluids, Lubricants, and Sealers .
8. Connect the customary brake pressure bleeder (2) to the brake pressure bleeder adapter (1).
9. Charge the brake pressure bleeder air tank to 175-205 kPa (25-30 psi).
10. Open the customary brake pressure bleeder (2), or equivalent, fluid tank valve to allow pressurised brake fluid to enter the brake system.

Note: Any brake fluid leaks identified require repair prior to completing this procedure.

11. Wait approximately 30 seconds, then inspect the entire hydraulic brake system in order to ensure that there are no existing external brake fluid leaks.
12. Install a proper ring spanner onto the RIGHT REAR wheel hydraulic circuit bleeder valve.
13. Install a transparent hose over the end of the bleeder valve.
14. Submerge the open end of the transparent hose into a transparent container partially filled with NEW brake fluid from a clean, sealed brake fluid container. Refer to Adhesives, Fluids, Lubricants, and Sealers .
15. Loosen the bleeder valve to purge air from the wheel hydraulic circuit. Allow fluid to flow until air bubbles stop flowing from the bleeder, then tighten the bleeder valve.
16. With the right rear wheel hydraulic circuit bleeder valve tightened securely, after all air has been purged from the right rear hydraulic circuit, install a proper ring spanner onto the LEFT FRONT wheel hydraulic circuit bleeder valve.
17. Install a transparent hose over the end of the bleeder valve, then repeat steps 13–14.
18. With the left front wheel hydraulic circuit bleeder valve tightened securely, after all air has been purged from the left front hydraulic circuit, install a proper ring spanner onto the LEFT REAR wheel hydraulic circuit bleeder valve.
19. Install a transparent hose over the end of the bleeder valve, then repeat steps 13–14.
20. With the left rear wheel hydraulic circuit bleeder valve tightened securely, after all air has been purged from the left rear hydraulic circuit, install a proper ring spanner onto the RIGHT FRONT wheel hydraulic circuit bleeder valve.
21. Install a transparent hose over the end of the bleeder valve, then repeat steps 13–14.
22. After completing the final wheel hydraulic circuit bleeding procedure, ensure that each of the 4 wheel hydraulic circuit bleeder valves are properly tightened.
23. Close the customary brake pressure bleeder fluid tank valve, then disconnect the bleeder (2) from the bleeder adapter (1).
24. Remove the customary brake pressure bleeder adapter (1) from the brake master cylinder reservoir.
25. Install the brake master cylinder reservoir cap.
26. Fill the brake master cylinder reservoir to the maximum-fill level with NEW brake fluid from a clean, sealed brake fluid container. Refer to Adhesives, Fluids, Lubricants, and Sealers .
27. Slowly depress and release the brake pedal. Observe the feel of the brake pedal.
28. If the brake pedal feels spongy, perform the following steps:

28.1.

Inspect the brake system for external leaks. Refer to Brake System External Leak Inspection .

28.2.

If equipped with antilock brakes, using a scan tool, perform the antilock brake system automated bleeding procedure to remove any air that may have been trapped in the BPMV.

Note: If the brake system warning lamp remains illuminated, DO NOT allow the vehicle to be driven until it is diagnosed and repaired.

29. Turn the ignition key ON, with the engine OFF. Check to see if the brake system warning lamp remains illuminated.
30. If the brake system warning lamp remains illuminated, refer to Symptoms - Hydraulic Brakes .