- consignment key for the fitting for bleeding the hydraulic drive of the brake mechanism;
- transparent hose and container for collecting brake fluid.
Materials needed: 1.2 liters of DOT 4 brake fluid.
Brake fluid absorbs moisture from the air through the pores in the brake hoses. This eventually leads to a decrease in the boiling point of the brake fluid.
With a heavy load on the brakes in such cases, vapor locks can form in the pipelines, which significantly impairs the functioning of the brake system.
Brake fluid should be changed every 2 years, preferably in the spring.
When driving frequently in mountainous terrain, the brake fluid should be changed at shorter intervals.
Attention! The procedure for changing the brake fluid is generally almost the same as for bleeding (pumping) from the braking system. For this reason, only the differences are given below.
1. Mark the level of brake fluid with a marker on the reservoir so that after replacing the previous level with fresh, keep the same. This technique allows you to avoid leakage of brake fluid from the reservoir when installing new brake pads (see illustration).
2. Take the maximum amount of brake fluid from the expansion tank using syringe 1. In this case, the tank should not be completely empty. It should leave a certain amount of brake fluid with a thickness of at least 10 mm (see illustration 24.1).
Attention! It is not allowed to remove the sieve from the brake fluid reservoir. Reuse of the selected brake fluid is also not allowed.
3. Fill the reservoir with fresh brake fluid up to the maximum mark.
4. Pump out the old brake fluid from all wheel brake cylinders / calipers, performing pumping one by one until a clear fluid without bubbles comes out of the caliper. Approximately 250 cm should flow out of the fitting of each caliper3 (1/4 l) brake fluid.
Attention! As fluid is removed through the fittings, add fluid to the expansion tank. It must not be allowed to empty, because in this case air will enter the brake system. If this still happens, then bleed the brake system in a workshop, because a tester connected to the diagnostic connector is required to bleed the ABS hydraulics.
5. Check up idling of a pedal of a brake after replacement of a brake liquid. Pedal free play should not exceed 1/3 of the total pedal travel.
Removing brake fluid from the clutch actuator
Due to the fact that the clutch drive is also carried out from the brake fluid, the old clutch fluid must also be removed from the clutch drive.
6. Remove the protective cap from the clutch slave cylinder bleeder 1 and clean the bleeder (see illustration).
7. Put a clean transparent hose on the fitting (see arrow in illustration 24.6), the other end of which is lowered into a bottle half filled with brake fluid.
8. Open the fitting and ask the assistant to squeeze out the clutch pedal. Approximately 0.1 liters of brake fluid should flow out of the drive.
9. Tighten the fitting while keeping the clutch pedal depressed.
10. Release the clutch pedal.
11. Slowly depress the clutch pedal 10-15 times until it stops and release.
12. Open the fitting and ask the assistant to squeeze out the clutch pedal. At the same time, approximately 0.05 l should flow out of the actuator (50 cm3 or 50 ml) brake fluid.
13. Tighten the fitting while keeping the clutch pedal depressed.
14. Release the clutch pedal.
15. Squeeze the clutch pedal several times to the stop and release.
16. Remove the hose from the fitting and place the bottle away from the work site.
17. Add brake fluid to the reservoir to the mark that indicated its previous level.
18. Screw the lid onto the tank.
Attention! Make sure that:
- A) brake hoses are securely connected;
- b) there is enough brake fluid in the expansion tank.
19. Check the tightness of the brake system by starting the engine, depress the brake pedal with a force of 200-300 N (20-30 kg) and hold it for about 10 seconds.
The pressure in the system and, accordingly, the resistance of the brake pedal, should not decrease. Check all connections for tightness.
20. Apply a few brakes on a light road. At least one braking operation must be performed so that the ABS is activated, which is felt by the pulsation of the brake pedal.
Attention! When checking the brake system in this way, take into account the situation on the road and keep an eye on the traffic behind you.
Visitor comments