HHR L4-2.4L (2010)
Brake Bleeding: Service and Repair
Hydraulic Brake Bleeding (Manual)
Hydraulic Brake System Bleeding (Manual)
Warning: Refer to Brake Fluid Irritant Warning (See: Service Precautions/Technician Safety Information/Brake Fluid Irritant Warning).
Caution: Refer to Brake Fluid Effects on Paint and Electrical Components Caution (See: Service Precautions/Vehicle Damage Warnings).
1. Place a clean shop cloth beneath the brake master cylinder reservoir to catch 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, to deplete the brake
booster power reserve.
3. If you have performed a master cylinder bench bleeding on this vehicle, or if you have 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.
1. Fill the master cylinder reservoir (combined with the hydraulic clutch (on manual (transmission) to the maximum-full level with GM approved
or equivalent brake fluid from a clean, sealed brake fluid container.
If removal of the reservoir cap and diaphragm is necessary, clean the outside of the reservoir on and around the cap prior to removal.
2. With the brake pipes installed securely to the master cylinder, proportioning valve assembly, or the brake modulator assembly, loosen and
separate one of the brake pipes from the port of the component.
Note: For the proportioning valve assembly or the brake modulator assembly, perform these steps in the sequence of system flow; begin with
the fluid feed pipes on the master cylinder.
3. Allow a small amount of brake fluid to gravity bleed from the open port of the component.
4. Connect the brake pipe fitting to the component and tighten securely.
5. Have an assistant slowly depress the brake pedal fully and maintain steady pressure on the brake pedal.
6. Loosen the same brake pipe fitting to purge air from the open port of the component.
7. Tighten the brake pipe fitting, then have the assistant slowly release the brake pedal.
8. Wait 15 seconds, then repeat steps 3.3-3.7 until all air is purged from the same port of the component.
9. With the brake pipe fitting installed securely to the master cylinder, proportioning valve assembly, or brake modulator assembly after all air
been purged from the first port of the component that was bled, loosen and separate the next brake pipe from the component and repeat steps
3.3-3.8 until each of the ports on the component has been bled.
10. After completing the final component bleeding procedure, ensure each of the brake pipe fittings is properly tightened.
4. Fill the master cylinder reservoir and combined hydraulic clutch, if equipped, to the maximum-full level with GM approved or equivalent brake
fluid from a clean, sealed brake fluid container. Ensure the master cylinder reservoir remains at least half-full during this bleeding procedure. 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.
5. Install a proper box-end wrench onto the RIGHT REAR wheel hydraulic circuit bleeder valve.
6. Install a transparent hose over the end of the bleeder valve.
7. Submerge the open end of the transparent hose into a transparent container partially filled with GM approved or equivalent brake fluid from a
clean, sealed brake fluid container.
8. Have an assistant slowly depress the brake pedal fully and maintain steady pressure on the brake pedal.
9. Loosen the bleeder valve to purge air from the wheel hydraulic circuit.
10. Tighten the bleeder valve, then have the assistant slowly release the brake pedal.
11. Wait 15 seconds, the repeat steps 8-10 until all air is purged from the same wheel hydraulic circuit.
12. With the right rear wheel hydraulic circuit bleeder valve tightened securely and after all air has been purged from the right rear wheel hydraulic
circuit, install a proper box-end wrench onto the LEFT FRONT wheel hydraulic circuit bleeder valve.
13. For Cobalt SS, install a proper box-end wrench onto the LEFT FRONT wheel hydraulic circuit INBOARD bleeder valve.
14. Install a transparent hose over the end of the bleeder valve, then repeat steps 7-11.
15. For Cobalt SS, install a proper box-end wrench onto the LEFT FRONT wheel hydraulic circuit, OUTBOARD bleeder valve.
16. For Cobalt SS, install a transparent hose over the end of the bleeder valve, then repeat steps 7-11.
17. With the left front wheel hydraulic circuit bleeder valve tightened securely and after all air has been purged from the left front wheel hydraulic
circuit, install a proper box-end wrench onto the LEFT REAR wheel hydraulic circuit bleeder valve.
18. Install a transparent hose over the end of the bleeder valve, then repeat steps 7-11.
19. With the left rear wheel hydraulic circuit bleeder valve tightened securely and after all air has been purged from the left rear wheel hydraulic
circuit, install a proper box-end wrench onto the RIGHT FRONT wheel hydraulic circuit bleeder valve.
20. For Cobalt SS, install a proper box-end wrench onto the RIGHT FRONT wheel hydraulic circuit INBOARD bleeder valve.
21. Install a transparent hose over the end of the bleeder valve, then repeat steps 7-11.
22. For Cobalt SS, install a proper box-end wrench onto the RIGHT FRONT wheel hydraulic circuit, OUTBOARD bleeder valve.
23. Install a transparent hose over the end of the bleeder valve, then repeat steps 7-11.
24. After completing the final wheel hydraulic circuit bleeding procedure, ensure each of the 4 wheel hydraulic circuit bleeder valves is properly
tightened.
25. For Cobalt SS, after completing the final wheel hydraulic circuit bleeding procedure, ensure each of the 6 wheel hydraulic circuit bleeder valves is
properly tightened.
