Bleeding the brake system (Opel Vectra C)

Warning! Wear protective glasses when bleeding the brake system. If brake fluid accidentally gets into your eyes, rinse them immediately with plenty of water and seek medical help!

1. Bleeding the hydraulic system is performed in order to remove air from it that gets into the system when servicing the brake mechanisms, replacing hydraulic lines or the master cylinder, and also when the fluid level in the master cylinder reservoir drops below the minimum permissible value.

2. If air has entered the system due to a drop in the fluid level in the brake master cylinder reservoir, or when the brake lines are disconnected from the brake master cylinder, the brake mechanisms of all four wheels must be bled. When disconnecting the line from any of the calipers/wheel cylinders, it will be sufficient to bleed only that specific brake mechanism. If the brake line was disconnected from the nipple located between the brake master cylinder and one of the brake mechanisms, only that part of the brake circuit must be bled.

3. All models considered in this Manual are equipped with ABS as standard. For high-quality and guaranteed bleeding of the hydraulic drive, as well as for the clutch drive (see Chapter 6. Section 4), a special bleeding kit must be used - carefully read the instructions for its use before starting work.

4. Press the foot brake pedal several times with the engine off to relieve any residual vacuum in the brake booster.

5. Remove the brake fluid reservoir cap and install the appropriate adapter for connecting the bleeding device instead. Connect the second hose of the device to the bleeding valve of the corresponding brake mechanism (see illustration). Turn on the device and open the valve. Continue bleeding until the air bubbles stop coming out of the brake tract, then first close the valve and then turn off the device. If necessary, repeat the procedure for the remaining brake mechanisms.





6. After bleeding, add fresh brake fluid to the master cylinder reservoir, bringing its level to normal. Never add used brake fluid to the reservoir - it is highly hygroscopic and over time absorbs a lot of moisture, which leads to a drop in its boiling point and, as a result, to a decrease in braking efficiency. In addition, the presence of moisture in the hydraulic system contributes to accelerated aging of the material of flexible brake hoses.

7. Check the efficiency of the brakes. Press the brake pedal with a force of approximately 20-30 kgf/cm¹ and hold it down for about 10 seconds. The pedal should provide firm resistance - a feeling of softness of its movement, as well as a gradual lowering of the pedal during the specified time indicates the presence of air in the hydraulic circuits and the need to repeat the bleeding procedure.

8. Take a test drive on a road with low traffic volume, make sure that the brake mechanisms operate reliably. To check the ABS operation, accelerate the car to a speed of 40-50 km/h, fully depress the brake pedal and hold it in this position until the car comes to a complete stop - the car should maintain directional stability, the wheels should not lock or skid. When the ABS is operating, you will feel the brake pedal pulsating, and a characteristic noise will be heard in the engine compartment.

Attention: Before braking, make sure that there is no possibility of creating an emergency situation or interfering with other road users!

9. Check the brake system for leaks, correct the cause if necessary, bleed and check the system again.

Attention: Never operate the vehicle unless you are absolutely sure that the brake system is functioning properly!

Emergency pumping method (assistant assistance required)

10. In some cases, when the bleeding kit is not available, but it is necessary to continue the trip, if air gets into the hydraulic tract of the service brake system drive, you can use the method below.

Note: On models equipped with ABS, this method does not provide a 100% guarantee of complete removal of air from the system - be especially careful when continuing to drive!

11. Before starting the procedure, check the brake fluid level in the reservoir and, if necessary, bring it up to the "MAX" mark.

Note: Do not forget to regularly check the fluid level in the reservoir before bleeding. An excessive drop in the level may result in air entering the master cylinder, which will nullify all efforts and will entail the need to bleed the entire brake system.

12. With the help of an assistant, have a supply of fresh brake fluid, a clear container partially filled with brake fluid, a length of plastic hose that fits snugly over the bleeder valve, and a suitable open-end/box wrench to loosen/tighten the valve.

13. Remove the dust cap and loosen the bleed valve slightly (see illustration 13.5) brake mechanism of the left front wheel, then tighten it again so that it releases easily and quickly during the procedure.

Note: It is recommended to apply a rust remover to the valves 1 hour before starting the bleeding procedure!

14. Attach a suitable plastic or rubber hose to the valve. To prevent air from entering the brake system, the other (free) end of the hose should be immersed in a container with brake fluid (see accompanying illustration). The end of the hose should be completely immersed in the liquid, and the container with the liquid should be located higher than the bleed valve.



15. Ask an assistant to slowly depress the foot brake pedal several times, thereby increasing the pressure in the system.

16. With the brake pedal locked in the lower position, open the bleeder valve just enough to start forcing brake fluid out of it. Watch the fluid coming out of the hose. After a few seconds, when the pressure weakens, close the valve and allow the assistant to release the pedal.

17. Repeat the procedures of the last two paragraphs until the fluid starts to flow out of the valve free of air bubbles, then move on to the brake mechanism of the right front wheel. Proceeding in a similar manner, bleed this mechanism, then the mechanisms of the left rear wheel and, finally, the right rear wheel.

Caution: Always ensure that the liquid level in the GHZ reservoir does not drop too low, and make appropriate adjustments if necessary!