- Ring wrench for bleed valve. For example, HAZET 1968-7.
- Transparent plastic hose with an inner diameter of 6 mm and a container for collecting brake fluid.
- About 1.0 liters of brake fluid.
DOT 5 specification brake fluid must not be used. Do not use used fluid in the system.
Observe the rules for handling brake fluid, refer to Section Brake fluid - basic information and safety measures.
Protect the environment, never throw away used oil or dispose of it with household waste. Local authorities should inform about the locations of the nearest collection points for waste materials.
Brake fluid absorbs moisture through the pores of the brake hoses, as well as the vent holes in the fluid reservoir. As a result, during operation, the boiling point of the brake fluid decreases. If the brakes are heavily loaded, this can lead to the formation of steam bubbles in the brake pipes, which reduces the effectiveness of the brakes. Therefore, it is necessary to change the brake fluid every 2 years.
1. Observe the rules for handling brake fluid, as set out in Section Brake fluid - basic information and safety measures.
At service stations, air from the hydraulic brake system is usually removed using a special device. The device supplies brake fluid to a reservoir at a pressure of 2.0 bar. This operation can be carried out without the use of a special tool. In this case, the air from the brake system is removed by rocking the brake pedal. The operation is performed with the help of an assistant.
If air has entered the ABS valve body, it is recommended that it be removed by a workshop. This occurs when there is a leak in the valve body, or when one chamber of the brake fluid reservoir is empty, or when you forgot to add fluid when bleeding the system.
2. Mark the liquid level on the reservoir. After replacing the fluid, restore the previous fluid level. This prevents the tank from overflowing with liquid when replacing the brake pads.
3. Suck out the liquid from the tank to a level of 10 mm.
4. Fill the reservoir with fresh brake fluid up to the MAX mark.
Carefully open the bleeder fittings so as not to unscrew them. It is recommended to spray the fittings about two hours before opening with a rust remover. If any fitting does not turn away, you must contact the service station.
Bleeding sequence
1. Rear right caliper.
2. Rear left caliper.
3. Front right caliper.
4. Caliper front left.
5. Put a clean hose on the fitting of the right rear brake cylinder and substitute the appropriate container.
6. Ask an assistant to slowly press the brake pedal so that you feel resistance.
7. Keeping the brake pedal depressed, unscrew the fitting with a wrench -1- on the right rear caliper. Close the fitting when the pedal touches the floor. Ask an assistant to release the pedal.
8. Repeat the described procedure as many times as necessary to ensure that the liquid that comes out does not contain bubbles. Fresh fluid is recognizable by its light color.
9. Lightly tighten the fitting. The tightening torque depends on the thread diameter: a fitting with a diameter of 7 mm is tightened with a torque of 5 Nm, a diameter of 11 mm with a torque of 15 Nm.
10. Similarly, in the order specified above, pump out a brake liquid from other supports.
Add fluid to the reservoir while bleeding. It should not be completely empty. Otherwise, air will enter the system.
11. After replacing the brake fluid, press the brake pedal and check its free play. It should not exceed 1/3 of the total pedal travel.
12. Cars with manual transmission: Since the clutch drive is powered by brake fluid, the fluid in the clutch hydraulic system is replaced in the manner described above.
13. Before changing the brake fluid, fill it in the reservoir to the marked level.
14. Screw the cap onto the reservoir.
- Are the brake lines secured?
- Is the brake hose secured in the holder?
- Are the bleed fittings tight?
- Has sufficient brake fluid been added?
With the engine running, check for leaks. To do this, press the brake pedal with a force of 200 - 300 N (20 – 30 kg) within 10 s. The pedal must not loosen. Check all connections for tightness.
15. Finally, brake a few times on a road with little traffic. At the same time, apply full braking at least once, which activates the ABS, in particular on the ground. The operation of the ABS is felt by the pulsations of the brake pedal.