Isuzu Amigo / Axiom / Trooper / Rodeo / VehiCross. Manual - part 171

5C–1

POWER–ASSISTED BRAKE SYSTEM

AXIOM (Vehicles Produced Before July/31/2001)

BRAKES

POWER-ASSISTED BRAKE SYSTEM

CONTENTS

Service Precaution

5C–2

. . . . . . . . . . . . . . . . . . . . . . 

General Description

5C–2

. . . . . . . . . . . . . . . . . . . . . 

Diagnosis

5C–6

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

General Diagnosis

5C–7

. . . . . . . . . . . . . . . . . . . . . . . 

Hydraulic Brakes

5C–10

. . . . . . . . . . . . . . . . . . . . . . . . 

Filling Master Cylinder Reservoir

5C–10

. . . . . . . . 

Deterioration of Brake Fluid

5C–10

. . . . . . . . . . . . . 

Leakage of Brake Fluid

5C–10

. . . . . . . . . . . . . . . . . 

Bleeding Brake Hydraulic System

5C–10

. . . . . . . . 

Flushing Brake Hydraulic System

5C–11

. . . . . . . . 

Brake Pipes and Hoses

5C–11

. . . . . . . . . . . . . . . . 

Brake Hose Inspection

5C–11

. . . . . . . . . . . . . . . . . 

Front Caliper Brake Hose

5C–12

. . . . . . . . . . . . . . . . 

Front Caliper Brake Hose and Associated
 Parts

5C–12

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Removal

5C–12

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Installation

5C–12

. . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Rear Axle Brake Hose

5C–13

. . . . . . . . . . . . . . . . . . . 

Rear Axle Brake Hose and Associated
 Parts

5C–13

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Removal

5C–13

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Installation

5C–13

. . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Brake Pipe

5C–14

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Removal

5C–14

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Installation

5C–14

. . . . . . . . . . . . . . . . . . . . . . . . . . . . 

P & B (Proportioning and Bypass) Valve

5C–15

. . . . 

P & B (Proportioning and Bypass) Valve
 Sectional View

5C–15

. . . . . . . . . . . . . . . . . . . . . . . . 

Removal

5C–15

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Installation

5C–15

. . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Main Data and Specifications

5C–16

. . . . . . . . . . . . . 

Brake Pedal

5C–17

. . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Checking Pedal Height

5C–17

. . . . . . . . . . . . . . . . . 

Checking Pedal Travel

5C–17

. . . . . . . . . . . . . . . . . 

Brake Pedal and Associated Parts

5C–18

. . . . . . . 

Removal

5C–18

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Installation

5C–18

. . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Stoplight Switch

5C–19

. . . . . . . . . . . . . . . . . . . . . . . . . 

Parts Location

5C–19

. . . . . . . . . . . . . . . . . . . . . . . . 

Removal

5C–19

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Installation

5C–19

. . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Main Data and Specifications

5C–20

. . . . . . . . . . . . . 

Fluid Reservoir Tank

5C–21

. . . . . . . . . . . . . . . . . . . . . 

Fluid Reservoir Tank and Associated Parts

5C–21

Removal

5C–21

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Installation

5C–21

. . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Master Cylinder Assembly

5C–22

. . . . . . . . . . . . . . . . 

Master Cylinder Assembly and Associated
 Parts

5C–22

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Removal

5C–22

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Inspection and Repair

5C–22

. . . . . . . . . . . . . . . . . . 

Installation

5C–23

. . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Main Data and Specifications

5C–24

. . . . . . . . . . . 

Special Tools

5C–24

. . . . . . . . . . . . . . . . . . . . . . . . . . 

Vacuum Booster Assembly

5C–25

. . . . . . . . . . . . . . . 

Vacuum Booster Assembly and Associated
 Parts

5C–25

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Removal

5C–25

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Inspection and Repair

5C–26

. . . . . . . . . . . . . . . . . . 

Installation

5C–26

. . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Exterior Components

5C–28

. . . . . . . . . . . . . . . . . . . . 

Exterior Components and Associated Parts

5C–28

Removal

5C–28

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Inspection and Repair

5C–29

. . . . . . . . . . . . . . . . . . 

Installation

5C–29

. . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Vacuum Booster Overhaul

5C–29

. . . . . . . . . . . . . . . . 

Vacuum Booster

5C–29

. . . . . . . . . . . . . . . . . . . . . . . 

Main Data and Specifications

5C–30

. . . . . . . . . . . . . 

Special Tools

5C–31

. . . . . . . . . . . . . . . . . . . . . . . . . . . 

Front Disc Brake Pads

5C–32

. . . . . . . . . . . . . . . . . . . 

Front Disc Brake Pads Inspection

5C–32

. . . . . . . . 

Front Disc Brake Pads and Associated
 Parts

5C–32

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Removal

5C–33

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Installation

5C–33

. . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Front Disc Brake Rotor

5C–35

. . . . . . . . . . . . . . . . . . . 

Inspection

5C–35

. . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Replacing Brake Rotors

5C–35

. . . . . . . . . . . . . . . . 

Refinishing Brake Rotors

5C–35

. . . . . . . . . . . . . . . 

Front Disc Brake Caliper Assembly

5C–36

. . . . . . . . 

Front Disc Brake Caliper Assembly and
 Associated Parts

5C–36

. . . . . . . . . . . . . . . . . . . . . . 

Removal

5C–37

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Installation

5C–37

. . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Front Disc Brake Caliper

5C–39

. . . . . . . . . . . . . . . . . 

Front Disc Brake Caliper Disassembled
 View

5C–39

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Disassembly

5C–39

. . . . . . . . . . . . . . . . . . . . . . . . . . 

SECTION

5C–2

POWER–ASSISTED BRAKE SYSTEM

Inspection and Repair

5C–40

. . . . . . . . . . . . . . . . . . 

Reassembly

5C–40

. . . . . . . . . . . . . . . . . . . . . . . . . . 

Main Data and Specifications

5C–42

. . . . . . . . . . . 

Rear Disc Brake Pads (4

×

4 Model)

5C–43

. . . . . . . . 

Brake Pads Inspection

5C–43

. . . . . . . . . . . . . . . . . 

Brake Pads and Associated Parts

5C–43

. . . . . . . 

Removal

5C–44

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Installation

5C–44

. . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Rear Disc Brake Rotor (4

×

4 Model)

5C–46

. . . . . . . . 

Inspection

5C–46

. . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Replacing Brake Rotors

5C–46

. . . . . . . . . . . . . . . . 

Refinishing Brake Rotors

5C–46

. . . . . . . . . . . . . . . 

Rear Drum (In Disc) Inside Diameter Check

5C–47

Rear Disc Brake Caliper Assembly
 (4

×

4 Model)

5C–48

. . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Rear Disc Brake Caliper Assembly and
 Associated Parts

5C–48

. . . . . . . . . . . . . . . . . . . . . . 

Removal

5C–48

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Installation

5C–49

. . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Rear Disc Brake Caliper (4

×

4 Model)

5C–50

. . . . . . 

Rear Disc Brake Caliper Disassembled
 View

5C–50

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Disassembly

5C–51

. . . . . . . . . . . . . . . . . . . . . . . . . . 

Inspection and Repair

5C–51

. . . . . . . . . . . . . . . . . . 

Reassembly

5C–51

. . . . . . . . . . . . . . . . . . . . . . . . . . 

Main Data and Specifications (4

×

4 Model)

5C–53

Brake Lining

5C–54

. . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Brake Lining and Associated Parts

5C–54

. . . . . . . 

Removal

5C–54

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Brake Lining Inspection

5C–55

. . . . . . . . . . . . . . . . 

Installation

5C–55

. . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Drum Brake Adjustment (4

×

2 Model)

5C–56

. . . . . 

Servicing The Brake Drum

5C–56

. . . . . . . . . . . . . . 

Wheel Cylinder Assembly (4

×

2 Model)

5C–57

. . . . . 

Wheel Cylinder Assembly and Associated
 Parts

5C–57

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Removal

5C–57

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Installation

5C–57

. . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Disassembled View

5C–58

. . . . . . . . . . . . . . . . . . . . 

Disassembly

5C–58

. . . . . . . . . . . . . . . . . . . . . . . . . . 

Inspection and Repair

5C–58

. . . . . . . . . . . . . . . . . . 

Reassembly

5C–58

. . . . . . . . . . . . . . . . . . . . . . . . . . 

Main Data and Specifications

5C–60

. . . . . . . . . . . 

Service Precaution

WARNING: THIS VEHICLE HAS A SUPPLEMENTAL
RESTRAINT SYSTEM (SRS).  REFER TO THE SRS
COMPONENT AND WIRING LOCATION VIEW IN
ORDER TO DETERMINE WHETHER YOU ARE
PERFORMING SERVICE ON OR NEAR THE SRS
COMPONENTS OR THE SRS WIRING. WHEN YOU
ARE PERFORMING SERVICE ON OR NEAR THE SRS
COMPONENTS OR THE SRS WIRING, REFER TO
THE SRS SERVICE INFORMATION. FAILURE TO
FOLLOW WARNINGS COULD RESULT IN POSSIBLE
AIR BAG DEPLOYMENT, PERSONAL INJURY, OR
OTHERWISE UNNEEDED SRS SYSTEM REPAIRS.

CAUTION: Always use the correct fastener in the
proper location. When you replace a fastener, use
ONLY the exact part number for that application.
ISUZU will call out those fasteners that require a
replacement after removal. ISUZU will also call out
the fasteners that require thread lockers or thread
sealant. UNLESS OTHERWISE SPECIFIED, do not
use supplemental coatings (Paints, greases, or other
corrosion inhibitors) on threaded fasteners or
fastener joint interfaces. Generally, such coatings
adversely affect the fastener torque and the joint
clamping force, and may damage the fastener. When
you install fasteners, use the correct tightening
sequence and specifications. Following these
instructions can help you avoid damage to parts and
systems.

General Description

Master Cylinder Assembly

330RS001

5C–3

POWER–ASSISTED BRAKE SYSTEM

The master cylinder contains two pistons that supply the
hydraulic pressure for a dual–circuit braking system. The
primary piston provides the fluid pressure to the front
brakes, while the secondary piston provides the fluid
pressure to the rear brakes. If the pressure is lost from
either system, the remaining system will function to stop
the vehicle.

CAUTION:
1. The master cylinder is not repairable. If found

defective, it must be replaced as a complete
assembly.

2. If any hydraulic component is removed or

disconnected, it may be necessary to bleed all or
part of the brake system. (Refer to 

Bleeding Brake

Hydraulic System in this section.)

3. The torque values specified are for dry,

unlubricated fasteners.

4. Perform service operations on a clean bench free

from all mineral oil materials.

Brake Booster

331RS001

This booster is a tandem vacuum unit with a diaphragm
effective diameter 205mm (8.072 in) + 230mm (9.056 in).
In normal operating mode, with the service brakes in the
released position, the tandem vacuum booster operates
with vacuum on both sides of its diaphragms. When the
brakes are applied, air at atmospheric pressure is
admitted to both sides of the diaphragm to provide the
power assist. When the service brake is released, the
atmospheric air is shut off from both sides of the
diaphram. The air is then drawn from the booster through
the vacuum check valve to the vacuum source.

CAUTION:
1. If any hydraulic component is removed or

disconnected, it may be necessary to bleed all or
part of the brake system.

2. The torque values specified are for dry,

unlubricated fasteners.

3. The vacuum booster is not repairable and must be

replaced as complete assembly.

5C–4

POWER–ASSISTED BRAKE SYSTEM

Disc Brake

Front Disc Brake

A05RW001

Rear Disc Brake (4

×

4 Model)

A05RW002

The disc brake assembly consists of a caliper, piston,
rotor, pad assembly and support bracket. The caliper
assembly has a single bore and is mounted to the support
bracket with two mounting bolts. The support bracket
allows the caliper to move laterally against the rotor. The
caliper is a one–piece casting with the inboard side
containing the piston bore. A square cut rubber seal is
located in a groove in the piston bore which provides the
hydraulic seal between the piston and the cylinder wall.

NOTE:

1. Replace all components included in repair kits used to

service this caliper.

2. Lubricate rubber parts with clean brake fluid to ease

assembly.

3. If any hydraulic component is removed or

disconnected, it may be necessary to bleed all or part
of the brake system.

4. Replace pads in axle sets only.
5. The torque values specified are for dry, unlubricated

fasteners.

6. Perform the service operation on a clean bench free

from all mineral oil materials.

Operation
Hydraulic pressure, created by applying the brake pedal,
is converted by the caliper to a stopping force. This force
creates a clamping action of the piston pressing towards
the rotors (outward) and the caliper slides inward toward
the vehicle. This clamping action forces the linings
against the rotor, creating friction to stop the vehicle.