Opel Frontera UE. Manual - part 1391

 

  Index      Opel     Opel Frontera UE - service repair manual 1999-2001 year

 

Search            

 

 

 

 

 

 

 

 

 

Content   ..  1389  1390  1391  1392   ..

 

 

Opel Frontera UE. Manual - part 1391

 

 

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

SECTION

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 (8.07in + 9.06in). 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.

SECTION

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.

SECTION

POWER-ASSISTED BRAKE SYSTEM

5C–5

Diagnosis

Road Testing The Brakes

Brake Test

Brakes should be tested on a dry, clean, reasonably 
smooth and level roadway. A true test of brake 
performance cannot be made if the roadway is wet, 
greasy or covered with loose dirt so that all tires do not 
grip the road equally. Testing will also be adversely 
affected if the roadway is crowned so as to throw the 
weight of the vehicle toward wheels on one side or if the 
roadway is so rough that wheels tend to bounce. Test 
the brakes at different vehicle speeds with both light and 
heavy pedal pressure; however, avoid locking the 
wheels and sliding the tires. Locked wheels and sliding 
tires do not indicate brake efficiency, since heavily 
braked but turning wheels will stop the vehicle in less 
distance than locked wheels. More tire–to–road friction 
is present with a heavily braked turning tire then with a 
sliding tire.
The standard brake system is designed and balanced to 
avoid locking the wheels except at very high 
deceleration levels.
It is designed this way because the shortest stopping 
distance and best control is achieved without brake 
lock–up.
Because of high deceleration capability, a firmer pedal 
may be felt at higher deceleration levels.

External Conditions That Affect Brake Performance

1. Tires: Tires having unequal contact and grip on the 

road will cause unequal braking. Tires must be 
equally inflated, identical in size, and the thread 
pattern of right and left tires must be approximately 
equal.

2. Vehicle Loading: A heavily loaded vehicle requires 

more braking effort.

3. Wheel Alignment: Misalignment of the wheels, 

particularly in regard to excessive camber and 
caster, will cause the brakes to pull to one side.

Brake Fluid Leaks

With engine running at idle and the transmission in 
“Neutral", depress the brake pedal and hold a constant 
foot pressure on the pedal. If  pedal gradually falls away 
with the constant pressure, the hydraulic system may be 
leaking.
Check the master cylinder fluid level. While a slight drop 
in the reservoir level will result from normal lining wear, 
an abnormally low level in reservoir indicates a leak in 
the system. The hydraulic system may be leaking 
internally as well as externally. Refer to “

Master Cylinder 

Inspection

". Also, the system may appear to pass this 

test but still have slight leakage. If fluid level is normal, 
check the vacuum booster push rod length. If an 
incorrect length push rod is found, adjust or replace the 
push rod. Check the brake pedal travel and the parking 
brake adjustment.

When checking the fluid level, the master cylinder fluid 
level may be  low from the “MAX" mark if the front and 
rear linings are worn.  This is not abnormal.

Warning Light Operation

When the ignition switch is in the START position, the 
“BRAKE" warning light should turn on and go off when 
the ignition switch returns to the ON position.
The following conditions will activate the “BRAKE" light:

1. Parking brake applied. The light should be on 

whenever the parking brake is applied and the 
ignition switch is on.

2. Low fluid level. A low fluid level in the master 

cylinder will turn the “BRAKE" light on.

3. During engine cranking the “BRAKE" light should 

remain on. This notifies the driver that the warning 
circuit is operating properly.

SECTION

 

 

 

 

 

 

 

Content   ..  1389  1390  1391  1392   ..