Warning: This operation must be performed by two people, observing safety precautions, as brake fluid is toxic.
The order of pumping the entire system:
- rear right wheel;
- rear left wheel;
- front right wheel;
- front left wheel.
If work was carried out only on the brake of one wheel, then it is sufficient to bleed the cylinder of only that wheel.
Warning: Use only new brake fluid when topping up or replacing.
Execution order
1. Clean the air release valve on the wheel from which air will be removed from dirt and dust.
2. Check and, if necessary, add brake fluid to the reservoir up to the maximum mark.
3. Remove the protective cap from the air release valve and place a rubber hose onto the valve head to drain the fluid.
4. Place the end of the hose in a clean, transparent container partially filled with brake fluid.
5. Press the brake pedal sharply 4-5 times (with an interval of 1-2 seconds between presses), and then, keeping the pedal pressed, unscrew the air release valve by 1/2-3/4 of a turn. In this case, air bubbles will be visible in the liquid flowing out of the hose. After the liquid stops flowing out of the hose, tighten the air release valve tightly and release the brake pedal.
6. Repeat step 3 until the release of bubbles from the flowing fluid completely stops. In this case, it is necessary to monitor the level of brake fluid in the reservoir and add brake fluid to the reservoir, not allowing the level in it to decrease further.
7. Remove the hose, wipe the end of the valve and put the cap on it.
8. Bleed the brakes on the remaining wheels, if necessary.
9. Add brake fluid to the reservoir to the required level.
Warning: If the brake system has not been bled thoroughly enough, then when you press the pedal at the end of its travel, you will feel an increased "softness" of the pedal.
[The original article is posted on the resource: AudiManual.ru]