Checking the brake system (Opel Vectra C)

Warning! Remember that the dust generated by the brake mechanisms may contain asbestos, which is extremely harmful to human health. Never blow off dust with compressed air or inhale it; wear a protective mask or respirator when servicing the mechanisms. Never use gasoline or petroleum-based solvents to wipe brake system components - use only branded cleaning agents or methyl alcohol!

1. The condition of the brake system components, in addition to the regular checks specified in the routine maintenance schedule, must be assessed every time the wheels are removed or when signs of a malfunction in the brake system occur.

2. The following symptoms may indicate a faulty brake component:

• a) When braking, the car loses directional stability (there is a pull to one side);
• b) When braking, the brakes make a squealing or squeaking noise;
• c) The foot brake pedal travel increases excessively;
• d) There are traces of brake fluid leakage (usually on the inner surface of wheel rims and tires).

3. Loosen the wheel bolts.

4. Jack up and place the vehicle on supports or lift it on a lift.

5. Remove the wheels.

Disc brakes

6. The support of each brake mechanism is equipped with two pads (internal and external). When the wheel is removed, sufficient access is available for inspection and testing of the outer brake pad. The residual thickness of the friction lining of the inner pad is assessed visually through the inspection window of the caliper (see accompanying illustration) after removing the wheel.





7. The measurement of the residual size of the brake shoe linings is carried out using a ruler. Lining thickness (taking into account the thickness of the metal substrate) must be no less than 9 mm for front wheels and not less 8 mm for rear wheels (see Specifications). If the linings are worn beyond the permissible limit, it is necessary to perform a complete replacement of the brake pads.

Attention! All brake pads of one axle must be replaced at the same time, even if only one of them has reached the wear limit!

8. If there is any doubt about the condition of the linings or there is a need for a more detailed inspection of the brake pads, remove the caliper(s) and take out the pads for a more detailed examination (see Chapter 9).

9. After the pads have been removed from the caliper, clean them with a special agent and check the remaining thickness of the linings with a ruler or a caliper equipped with a vernier.

10. Measure the thickness of the brake discs with a micrometer. Compare the measurement results with the standard requirements (see Specifications). If the thickness of any of the discs is outside the acceptable range, replace it (see Chapter 9). If the disk thickness is normal, check its general condition. Pay attention to such defects as deep scratches, grooves, scuffs, traces of overheating, etc., if necessary, remove the disk and give it for turning (see Chapter 9).



11. Before reinstalling the wheels, inspect all brake lines for signs of damage, wear, degradation due to aging of the material, signs of leaks, kinks, twists and other deformations (especially near the points of connection of flexible brake hoses to the brake calipers. Check the reliability of the hose clamps. Make sure that none of the brake hoses come into contact with sharp corners of adjacent body elements, exhaust system components and suspension (at any steering wheel position). If necessary, make appropriate repairs or adjust the route of the lines. Replace defective components (see Chapter 9).

12. There is a practical way to calculate the brake pad life to plan their timely replacement. When operating a vehicle in difficult conditions (urban cycle, mountainous terrain, etc.) the front disc brakes have wear on the lining 1 mm approximately corresponds to the mileage 1000 km. Then, for example, with a thickness 5 mm (excluding the thickness of the metal substrate) the brake pad will last at least another3000 km mileage. Under normal operating conditions, the linings last much longer.

13. After completing the check, install the wheels in place, paying attention to the direction of the tread pattern, tighten the wheel bolts, lower the car and tighten the bolts in a diagonal order with the required force (110 Nm).

(Material copied from this portal: «OpelBook.ru»)

Vacuum booster

14. The proper functioning of the brake booster is checked from the driver's seat.

15. With the foot brake pedal fully depressed, start the engine - the pedal should still fall a little.



16. With the engine running, press the foot brake pedal several times. The pedal travel should remain constant.

17. Press the pedal, turn off the engine and continue to hold the pedal down for about 30 seconds, during which it should neither fall lower nor rise.

18. Start the engine again, let it run for a minute, then turn it off again. Press the pedal firmly several times again - the stroke should decrease with each stroke.

19. If the result of the described check is negative, the brake booster servo drive must be replaced (see Chapter 9).

Parking brake

20. The parking brake is set using a lever installed between the front seats. The functioning of the parking brake mechanism is checked with the vehicle fully suspended - the wheels must be at least 5 cm above the ground. Before starting work, make sure that the vehicle is securely secured.

21. Release the parking lever completely and manually check the freedom of rotation of the wheels.

22. Set the parking brake lever to 3 clicks - when rotating freely, the wheel should brake immediately, but when applying force, it should turn with difficulty. Braking of both wheels should be done with the same force.

23. If the above conditions are not met, make the necessary adjustments (see Chapter 9).

24. After inspection/adjustment, lubricate the parking brake drive cable guides with silicone grease Opel - 19 70 206 (90 167 353) and lower the car.

25. Alternatively, the parking brake can be checked for proper operation by parking the vehicle on a slope and holding it still with the parking brake with the gearbox in neutral. If the brake does not hold the vehicle when the lever is pulled the required number of clicks, it is necessary to make adjustments (see Chapter 9).