Hummer H3. Manual — part 1343

Fig. 55: Hydraulic Brake Booster Accumulator Replacement
Courtesy of GENERAL MOTORS CORP.

Hydraulic Brake Booster Accumulator Replacement

2007 Hummer H3

2007 BRAKES Hydraulic Brakes - H3

POWER BRAKE BOOSTER PUMP FLUID ACCUMULATOR DISPOSAL

Callout

Component Name

Fastener Tightening Specifications: Refer to Fastener Tightening
Specifications.Preliminary Procedure: Remove the brake master cylinder assembly with
power brake booster and chassis control module. Refer to Brake Master Cylinder with
Power Brake Booster and Chassis Control Module Replacement (LHD) or Brake
Master Cylinder with Power Brake Booster and Chassis Control Module
Replacement (RHD) .

CAUTION:

Refer to Bleed Procedure Caution .

CAUTION:

Refer to Brake Fluid Irritant Caution .

NOTE:

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

NOTE:

Refer to Fastener Notice .

1

Power Brake Booster Accumulator
Tip: Discard the accumulator properly by cutting the accumulator in half and
draining the brake fluid. Refer to Power Brake Booster Pump Fluid
Accumulator Disposal.

Tighten: 55 N.m (41 lb ft)

2

Power Brake Booster Pump Fluid Accumulator Seal
Tip: Lubricate with Super DOT-4, GM P/N 88958860 (Canadian P/N
88901244) or equivalent DOT-4 brake fluid from a clean, sealed brake fluid
container.

3

Power Brake Booster Pump Fluid Accumulator Fitting Spring

4

Power Brake Booster Pump Fluid Accumulator Fitting

2007 Hummer H3

2007 BRAKES Hydraulic Brakes - H3

Fig. 56: Power Brake Booster Pump Fluid Accumulator Disposal
Courtesy of GENERAL MOTORS CORP.

Power Brake Booster Pump Fluid Accumulator Disposal

Callout

Component Name

CAUTION:

Refer to Safety Glasses Caution .

CAUTION:

Refer to Brake Fluid Irritant Caution .

2007 Hummer H3

2007 BRAKES Hydraulic Brakes - H3

DESCRIPTION AND OPERATION

BRAKE WARNING SYSTEM DESCRIPTION AND OPERATION

Brake Warning Indicator

The instrument panel cluster (IPC) illuminates the brake warning indicator when one or more of
the following occurs:

The body control module (BCM) detects that the park brake is engaged. The IPC receives a
class 2 message from the BCM requesting illumination.

The electronic brake control module (EBCM) detects a low brake fluid condition. The IPC
receives a class 2 message from the EBCM requesting illumination.

The EBCM detects an ABS malfunction which disables dynamic rear proportioning (DRP).
The IPC receives a class 2 message from the EBCM requesting illumination.

The IPC performs the bulb check at the start of each ignition cycle. The brake warning
indicator illuminates for approximately 3 seconds before turning OFF.

The IPC detects a loss of class 2 communications with the BCM or with the EBCM.

HYDRAULIC BRAKE SYSTEM DESCRIPTION AND OPERATION

System Component Description

The hydraulic brake system consists of the following:

Fastener Tightening Specifications: Refer to Fastener Tightening
Specifications.Preliminary Procedure: Remove the power brake booster accumulator.
Refer to Hydraulic Brake Booster Accumulator Replacement.

NOTE:

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

1

Accumulator, Power Brake Booster
Tip:

1. Cover the accumulator with a cloth.

2. Using a hand saw, cut the accumulator body between A and B in order

to discharge the gas and fluid inside.

3. Discard both accumulator halves in the proper waste container.

2007 Hummer H3

2007 BRAKES Hydraulic Brakes - H3