Hummer H3. Manual — part 1312

BRAKE PEDAL EXCESSIVE EFFORT

Brake Pedal Excessive Effort

6

and/or damage and inspect the
brake pedal for a misaligned,
bent, and/or damaged condition.

2. Replace the brake pedal system

components that are worn, missing,
misaligned, bent or damaged.

Did you find and replace any worn,
missing, misaligned, bent or damaged
brake pedal system components?

Go to Step 8

Go to Step 7

7

1. Inspect the brake assist system for the

following conditions:

Vacuum leaks and/or
improperly operating check
valve, if equipped with vacuum
assist

Damaged or improperly
operating brake booster
assembly

2. Adjust, repair or replace components

as necessary. Refer to Brake Assist
System Diagnosis.

Did you find and correct a condition?

Go to Step 8

Go to
Diagnostic
Starting Point -
Hydraulic
Brakes

8

1. Install or connect components that

were removed or disconnected during
diagnosis.

2. Road test the vehicle in order to

confirm proper operation. Refer to
Brake System Vehicle Road Test.

Is the condition still present?

Go to Step 2

System OK

Step

Action

Yes

No

DEFINITION: Brake pedal requires an increased amount of input from the driver to obtain

2007 Hummer H3

2007 BRAKES Hydraulic Brakes - H3

good braking action and/or stopping distance is increased.

1

Were you sent here from the Hydraulic
Brake Symptom table?

Go to Step 2

Go to
Diagnostic
Starting Point -
Hydraulic
Brakes

2

1. Inspect the brake assist system for

the following conditions:

Vacuum leaks, if equipped
with vacuum power assist

Lack of lubrication, binding or
excessively worn pushrod or
pedal pivots or pivot bushings

Bent or damaged pedal
pushrod, pedal or pedal
bracket

Damaged or improperly
operating brake booster
assembly

2. Adjust, repair or replace

components as necessary. Refer to
Brake Assist System Diagnosis.

Did you find and correct a condition?

Go to Step 5

Go to Step 3

3

1. Inspect the hydraulic brake system

for the following conditions:

Binding caliper pistons

Internally damaged flexible
brake hoses; hindering fluid
flow

External brake fluid leaks

Kinked or damaged flexible
brake hoses and/or pipes

Internal brake fluid leaks;
improperly operating master
cylinder

2007 Hummer H3

2007 BRAKES Hydraulic Brakes - H3

Poor brake fluid quality; low
boiling point

2. Adjust, repair or replace

components as necessary. Refer to
Hydraulic Brake System
Diagnosis.

Did you find and correct a condition?

Go to Step 5

Go to Step 4

4

1. Inspect the disc brake system for the

following conditions:

Excessively worn linings

Glazed linings

Cracked, distorted or damaged
linings

Contaminated linings

Binding, damaged or
excessively worn caliper
hardware and/or lining
hardware

Lack of lubrication or
excessive corrosion on metal to
metal contact surfaces

Excessively worn or corroded
rotor friction surfaces

Glazed rotor friction surfaces

Hard spots, heat checks,
blueing discoloration of rotor
friction surfaces

2. Adjust, repair or replace

components as necessary. Refer to
Disc Brake System Diagnosis.

Did you find and correct a condition?

Go to Step 5

Go to
Diagnostic
Starting Point -
Hydraulic
Brakes

1. Install or connect components that

were removed or disconnected
during diagnosis.

2007 Hummer H3

2007 BRAKES Hydraulic Brakes - H3

BRAKES DRAG

Brakes Drag

5

2. Road test the vehicle in order to

confirm proper operation. Refer to
Brake System Vehicle Road Test.

Is the condition still present?

Go to Step 2

System OK

Step

Action

Yes

No

DEFINITION: Brake system does not fully release or has delayed release; vehicle motion
may be hindered by brake system without applying brakes.

1

Were you sent here from the Hydraulic
Brake Symptom table?

Go to Step 2

Go to
Diagnostic
Starting Point -
Hydraulic
Brakes

2

Is the vehicle equipped with an adjustable
stop lamp switch and/or an adjustable
cruise control release switch?

Go to Step 3

Go to Step 4

3

1. Inspect the stop lamp switch for

proper adjustment to ensure that the
brake pedal is fully releasing.

2. Inspect the cruise control release

switch, if equipped, for proper
adjustment to ensure that the brake
pedal is fully releasing.

Did you find and correct a condition?

Go to Step 14

Go to Step 4

4

Is the vehicle equipped with a drum-in-
rotor type of park brake system?

Go to Step 5

Go to Step 7

5

Ensure the park brake shoes are not
adjusted too tightly, possibly causing drag
under certain conditions.
Are the park brake shoes adjusted too
tightly?

Go to Step 6

Go to Step 7

1. Clean and inspect the park brake

shoes for excessive wear and/or

2007 Hummer H3

2007 BRAKES Hydraulic Brakes - H3