Opel Frontera UBS. Manual - part 2055

5C – 32 POWER ASSISTED BRAKE SYSTEM

(4) When the front brake system fails.

When there is a failure in the front brake system,
the fluid pressure from the front master cylinder
decreases. As a result, the balance between the
front and rear brake side fluid pressures is lost at
the control valve sleeve so that the control valve
sleeve moves upwards.
The control valve sleeve strikes against the piston,
thereby pushing the piston upwards.
Accordingly, the fluid pressure of the rear master
cylinder is not decreased and is applied directly to
the rear wheel cylinder to secure a sufficient
braking performance of the rear brakes. (See the
left figure.) 

Valve Maintenance
In the case of fluid leak or other abnormalities, faulty
valve should be replaced.

Note:
The load sensing proportioning valve is not
repairable and must be replaced as a complete
assembly.

ADJUSTMENT PROCEDURE OF LSPV

1. Adjust the rear axle weight by loading the

laggage compartmemt as necessary.

Rear Axle Weight

N (kg / lb)

10,300 (1,050 / 2,315)

Note:
The rear axle weight should be adjusted to the
specified value with a man seated in the driver seat.

Rear master cylinder
fluid Pressure

C05RW022

POWER ASSISTED BRAKE SYSTEM  5C – 33

2. Check the rear wheel cylinder fluid pressure.

Install the pressure gauge on bleeder screws on
the front and rear brakes.

a. Depress the brake pedal slowly until the front

wheel cylinder fluid pressure reaches 7845 kPa
(80 kg/cm

2

/ 114 psi)

Note:

• The brake pedal should be depressed

gradually until specified pressure is reached
without pumping or adjusting foot pressure.

• If the front wheel cylinder fluid pressure rises

abobe 7845 kPa (80 kg/cm

2

/ 114 psi), release

the pedal fully, then depress the pedal again.

b. Hold the front wheel cylinder fluid pressure at

7845 kPa (80 kg/cm

2

/ 114 psi) for 2 seconds,

check the rear wheel cylinder fluid pressure.

Rear wheel cylinder
fluid pressure

kPa (kg/cm

2

/ psi)

6374±539 (65±5.5 / 924±78)

c. If the rear wheel cylinder fluid pressure is not

within the specified range, adjust the fluid
pressure.

3. Adjust the rear wheel cylinder fluid pressure. 

The fluid pressure can be adjusted by the bolt
projection (1) or bolt projection (2).

a. If the fluid pressure is lower than specified

range, increase the dimention (1) or (2).

b. If the fluid pressure is higher than the specified

range, decrease the dimention (1) or (2).

Reference:

Dimention (1): The fluid pressure can be

adjusted about 196 kPa (2
kg/cm

2

/ 28 psi) by one turning

of the nut.

Dimention (2): The fluid pressure can be

adjusted about 98 kPa (1 kg/cm

2

/ 14 psi) by sliding the bolt
position (per 1 mm / 0.039 in).

4. Check the rear wheel cylinder fluid pressure. 

If the rear wheel cylinder fluid pressure is not
within the specified range, try the adjustment
again.

5. Bleed the brake hydraulic line and check the fluid

leak.

2

1

C05RW023

5C – 34 POWER ASSISTED BRAKE SYSTEM

BRAKE PEDAL REPLACEMENT

10

9

5

12

4

2

7

8

6

11

3

1

M/T

Removal Steps

1.

Shift knob

2.

Front console assembly

3.

Lower cluster assembly

4.

Instrument panel driver lower cover
assembly

5.

Anti-theft controller

6.

Stoplight switch connector

7.

Return spring

8.

Snap pin

9.

Pin

10. Nut
11. Pin, fulcrum
12. Brake pedal

Installation Steps

12. Brake pedal
11. Pin, fulcrum
10. Nut

9.

Pin

8.

Snap pin

7.

Return spring

6.

Stoplight switch connector

5.

Anti-theft controller

4.

Instrument panel driver lower cover
assembly

3.

Lower cluster assembly

2.

Front console assembly

1.

Shift knob

This illustration is based on the LHD model.

POWER ASSISTED BRAKE SYSTEM  5C – 35

REMOVAL

1. Shift Knob

2. Front Console Assembly

3. Lower Cluster Assembly

4. Instrument Panel Driver Lower Cover Assembly

5. Anti-theft Controller

6. Stoplight switch Connector

7. Return Spring

8. Snap Pin

9. Pin

10. Nut

11. Pin, Fulcrum

12. Brake Pedal

INSTALLATION

12. Brake Pedal

11. Pin, Fulcrum

•

Apply grease to the entire circumference of the
fulcrum pin.

10. Nut

Bolt and Nut Torque

N·m (kg·m / lb·ft)

33 (3.3 / 24)

9. Pin

•

Apply grease to the entire circumference of the
push rod pin.

8. Snap Pin

•

Adjust pedal free travel. Refer to “Brake Pedal
Adjustment” previously in this section.

7. Return Spring

6. Stoplight Switch Connector

5. Anti-theft Connector

4. Instrument Panel Driver Lower Cover Assembly

3. Lower Cluster Assembly

2. Front Console Assembly

1. Shift Knob