Opel Frontera UE. Manual - part 129

POWER-ASSISTED BRAKE SYSTEM

5C–1

BRAKES

POWER-ASSISTED BRAKE SYSTEM

CONTENTS

Service Precaution......................................... 5C - 2
General Description ....................................... 5C - 2
Diagnosis ....................................................... 5C - 5
General Diagnosis ......................................... 5C - 6

Hydraulic Brakes ........................................... 5C - 9

Filling Master Cylinder Reservoir................ 5C - 9
Deterioration of Brake Fluid ........................ 5C - 9
Leakage of Brake Fluid............................... 5C - 9
Bleeding Brake Hydraulic System .............. 5C - 9
Flushing Brake Hydraulic System............... 5C - 10
Brake Pipes and Hoses .............................. 5C - 10
Brake Hose Inspection ............................... 5C - 10

Front Caliper Brake Hose.............................. 5C - 11

Front Caliper Brake Hose and

Associated Parts ....................................... 5C - 11

Removal ..................................................... 5C - 11
Installation .................................................. 5C - 11

Rear Axle Brake Hose................................... 5C - 12

Rear Axle Brake Hose and

Associated Parts ....................................... 5C - 12

Removal ..................................................... 5C - 12
Installation .................................................. 5C - 12

Brake Pipe..................................................... 5C - 13

Removal ..................................................... 5C - 13
Installation .................................................. 5C - 13

P & B (Proportioning and Bypass) Valve ...... 5C - 14

P & B (Proportioning and Bypass) Valve 

Sectional View .......................................... 5C - 14

Removal ..................................................... 5C - 14
Installation .................................................. 5C - 14

Main Data and Specifications ........................ 5C - 15

Brake Pedal................................................... 5C - 16

Checking Pedal Height ............................... 5C - 16
Checking Pedal Travel ............................... 5C - 16
Brake Pedal and Associated Parts ............. 5C - 17
Removal ..................................................... 5C - 17
Installation .................................................. 5C - 17

Stoplight Switch............................................. 5C - 18

Parts Location............................................. 5C - 18
Removal ..................................................... 5C - 18
Installation .................................................. 5C - 18
Main Data and Specifications ..................... 5C - 19

Fluid Reservoir Tank ..................................... 5C - 20

Fluid Reservoir Tank and

Associated Parts ....................................... 5C - 20

Removal ..................................................... 5C - 20
Installation .................................................. 5C - 20

Master Cylinder Assembly ............................ 5C - 21

Master Cylinder Assembly and

Associated Parts ....................................... 5C - 21

Removal...................................................... 5C - 21
Inspection and Repair................................. 5C - 21
Installation................................................... 5C - 23

Main Data and Specifications ........................ 5C - 23
Special Tools ................................................. 5C - 23

Vacuum Booster Assembly ........................... 5C - 24

Vacuum Booster Assembly and 

Associated Parts ....................................... 5C - 24

Removal...................................................... 5C - 24
Inspection and Repair................................. 5C - 24
Installation................................................... 5C - 25

Exterior Components .................................... 5C - 27

Exterior Components and

Associated Parts ....................................... 5C - 27

Removal...................................................... 5C - 27
Inspection and Repair................................. 5C - 28
Installation................................................... 5C - 28

Vacuum Booster Overhaul ............................ 5C - 28

Vacuum Booster ......................................... 5C - 28

Main Data and Specifications ........................ 5C - 29
Special Tools ................................................. 5C - 30

Front Disc Brake Pads .................................. 5C - 31

Front Disc Brake Pads Inspection .............. 5C - 31
Front Disc Brake Pads and 

Associated Parts ....................................... 5C - 31

Removal...................................................... 5C - 32
Installation................................................... 5C - 32

Front Disc Brake Rotor.................................. 5C - 34

Inspection ................................................... 5C - 34
Replacing Brake Rotors.............................. 5C - 34
Refinishing Brake Rotors ............................ 5C - 34

Front Disc Brake Caliper Assembly............... 5C - 36

Front Disc Brake Caliper Assembly and 

Associated Parts ....................................... 5C - 36

Removal...................................................... 5C - 36
Installation................................................... 5C - 37

Front Disc Brake Caliper ............................... 5C - 39

Front Disc Brake Caliper 

Disassembled View................................... 5C - 39

Disassembly ............................................... 5C - 39
Inspection and Repair................................. 5C - 40
Reassembly ................................................ 5C - 40

Main Data and Specifications ........................ 5C - 42

Rear Disc Brake Pads ................................... 5C - 43

Brake Pads Inspection................................ 5C - 43
Brake Pads and Associated Parts .............. 5C - 43
Removal...................................................... 5C - 44
Installation................................................... 5C - 44

SECTION

5C–2

POWER-ASSISTED BRAKE SYSTEM

Rear Disc Brake Rotor .................................. 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 ............... 5C - 48

Rear Disc Brake Caliper Assembly and

Associated Parts ....................................... 5C - 48

Removal...................................................... 5C - 48
Installation................................................... 5C - 49

Rear Disc Brake Caliper................................ 5C - 51

Rear Disc Brake Caliper 

Disassembled View................................... 5C - 51

Disassembly ............................................... 5C - 51
Inspection and Repair................................. 5C - 52
Reassembly ................................................ 5C - 52

Main Data and Specifications ........................ 5C - 54

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

POWER-ASSISTED BRAKE SYSTEM

5C–3

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 + 230mm. 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 one side of each diaphragm to provide the 
power assist. When the service brake is released, the 
atmospheric air is shut off from the one side of each 
diaphragm. 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

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 acts equally against the piston and the 
bottom of the caliper bore to move the piston outward 
and to  move (slide) the caliper inward resulting in a 
clamping action on the rotor. This clamping action 
forces  the linings against the rotor, creating friction to 
stop the vehicle.