Hummer H3. Manual — part 1338

9. Wait approximately 30 seconds, then inspect the entire hydraulic brake system in order to

ensure that there are no existing external brake fluid leaks.

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

10. Install a proper box-end wrench onto the RIGHT REAR wheel hydraulic circuit bleeder

valve.

11. Install a transparent hose over the end of the bleeder valve.

12. Submerge the open end of the transparent hose into a transparent container partially filled

with brake and clutch fluid Super Dot-4, GM P/N 88958860 (Canadian P/N 88901244) or
equivalent DOT-4 brake fluid from a clean, sealed brake fluid container.

13. 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.

14. 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 box-end wrench onto the
LEFT REAR wheel hydraulic circuit bleeder valve.

15. Install a transparent hose over the end of the bleeder valve, then repeat steps 13-14.

16. 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 box-end wrench onto the
RIGHT 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 right front wheel hydraulic circuit bleeder valve tightened securely, after all air has

been purged from the right front hydraulic circuit, install a proper box-end wrench onto the
LEFT FRONT wheel hydraulic circuit bleeder valve.

19. Install a transparent hose over the end of the bleeder valve, then repeat steps 13-14.

20. After completing the final wheel hydraulic circuit bleeding procedure, ensure that each of

the 4 wheel hydraulic circuit bleeder valves are properly tightened.

21. Close the J 29532 or equivalent, fluid tank valve, then disconnect the J 29532 or

equivalent, from the J 44894-A . See Special Tools.

22. Remove the J 44894-A from the brake master cylinder reservoir. See Special Tools.

23. Fill the brake master cylinder reservoir. Refer to Master Cylinder Reservoir Filling.

24. Slowly depress and release the brake pedal. Observe the feel of the brake pedal.

25. If the brake pedal feels spongy perform the following steps:

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

Inspection .

2. Using a scan tool, perform the antilock brake system automated bleeding procedure to

2007 Hummer H3

2007 BRAKES Hydraulic Brakes - H3

remove any air that may have been trapped in the HBCi. Refer to Antilock Brake
System Automated Bleed Procedure .

26. Turn the ignition key ON, with the engine OFF. Check to see if the brake system warning

lamp remains illuminated.

27. If the brake system warning lamp remains illuminated, refer to Symptoms - Hydraulic

Brakes.

HYDRAULIC BRAKE SYSTEM FLUSHING (WITHOUT RPO BRM)

1. Inspect the brake fluid for the following conditions, indicating brake fluid contamination:

Fluid separation, indicating 2 types of fluid are present-A substance other than the
recommended brake fluid has been introduced into the brake hydraulic system.

Swirled appearance-Oil-based substance

Layered appearance-Silicone-based substance

Fluid discoloration, indicating the presence of moisture or particles that have been
introduced into the brake hydraulic system

Cloudy appearance-Moisture

Dark appearance/suspended particles in fluid-Dirt, rust, corrosion, brake dust

2. Inspect the master cylinder reservoir cap diaphragm and the reservoir-to-master cylinder

grommets for swelling, indicating brake fluid contamination.

3. If the brake fluid WAS contaminated with an oil-based or a silicone-based substance,

indicated by fluid separation and/or a swollen master cylinder reservoir cap diaphragm
and/or swollen reservoir-to-master cylinder grommets, perform the following:

1. Remove ALL of the following components listed from the vehicle. Each component

contains internal rubber seals/linings which have been contaminated by the
contaminated brake fluid in the brake hydraulic system.

IMPORTANT: If the brake system warning lamp remains illuminated, DO

NOT allow the vehicle to be driven until it is diagnosed and
repaired.

CAUTION: Refer to Brake Fluid Irritant Caution .

NOTE:

Refer to Brake Fluid Effects on Paint and Electrical Components
Notice .

2007 Hummer H3

2007 BRAKES Hydraulic Brakes - H3

Refer to the procedures indicated:

Brake Master Cylinder with Power Brake Booster and Chassis Control
Module Replacement (LHD) Brake Master Cylinder with Power Brake
Booster and Chassis Control Module Replacement (RHD)

Front Brake Hose Replacement

Rear Brake Hose Replacement

Front Brake Caliper Replacement

Rear Brake Caliper Replacement

2. Clean out all the hydraulic brake pipes using denatured alcohol or equivalent.

3. Dry the brake pipes using non-lubricated, filtered air.

4. Repair or replace ALL of the following components listed and install them to the

vehicle. Each component contains internal rubber seals/linings which have been
contaminated by the contaminated brake fluid in the brake hydraulic system.

Refer to the procedures indicated:

Clean the brake master cylinder reservoir using denatured alcohol or equivalent,
then dry the reservoir using non-lubricated, filtered air. Inspect the reservoir for
cracks and/or damage and replace if necessary. Refer to

Master Cylinder

Reservoir Replacement

.

Replace the brake master cylinder reservoir cap.

Front Brake Hose Replacement

Rear Brake Hose Replacement

Front Brake Caliper Overhaul or Front Brake Caliper Replacement

Rear Brake Caliper Overhaul or Rear Brake Caliper Replacement

HBCi components

4. If the brake fluid was NOT contaminated with an oil-based or a silicone-based substance,

but WAS contaminated with water or dirt, rust, corrosion, and/or brake dust, replace the
brake master cylinder reservoir cap which may have allowed the moisture or particles to
enter the hydraulic system.

5. Fill the brake master cylinder reservoir to the maximum-fill level with Delco Supreme 11®

(GM P/N 12377967) or equivalent DOT-3 brake fluid from a clean, sealed brake fluid
container.

6. Pressure bleed the hydraulic brake system. Begin the procedure with the pressure bleeder

2007 Hummer H3

2007 BRAKES Hydraulic Brakes - H3

reservoir filled to the maximum-fill level with the correct brake fluid as indicated. Refer to
Hydraulic Brake System Bleeding (Manual) or Hydraulic Brake System Bleeding
(Pressure).

HYDRAULIC BRAKE SYSTEM FLUSHING (WITH RPO BRM)

1. Inspect the brake fluid for the following conditions, indicating brake fluid contamination:

Fluid separation, indicating 2 types of fluid are present-A substance other than the
recommended brake fluid has been introduced into the brake hydraulic system.

Swirled appearance-Oil-based substance

Layered appearance-Silicone-based substance

Fluid discoloration, indicating the presence of moisture or particles that have been
introduced into the brake hydraulic system

Cloudy appearance-Moisture

Dark appearance/suspended particles in fluid-Dirt, rust, corrosion, brake dust

2. Inspect the master cylinder reservoir cap diaphragm and the reservoir-to-master cylinder

grommets for swelling, indicating brake fluid contamination.

3. If the brake fluid WAS contaminated with an oil-based or a silicone-based substance,

indicated by fluid separation and/or a swollen master cylinder reservoir cap diaphragm
and/or swollen reservoir-to-master cylinder grommets, perform the following:

1. Remove ALL of the following components listed from the vehicle. Each component

contains internal rubber seals/linings which have been contaminated by the
contaminated brake fluid in the brake hydraulic system.

Refer to the procedures indicated:

Brake Master Cylinder with Power Brake Booster and Chassis Control
Module Replacement (LHD) Brake Master Cylinder with Power Brake
Booster and Chassis Control Module Replacement (RHD)

CAUTION: Refer to DOT 4 BRAKE FLUID CAUTION

CAUTION: Refer to Brake Fluid Irritant Caution .

NOTE:

Refer to Brake Fluid Effects on Paint and Electrical Components
Notice .

2007 Hummer H3

2007 BRAKES Hydraulic Brakes - H3