Warning: Brake fluid can damage your eyes and paintwork, so be careful when working with the brake system. Do not use fluid that has been stored in an open container for a long time, because brake fluid is hygroscopic and absorbs moisture from the air. Excess moisture in the brake fluid can significantly reduce the effectiveness of the brakes.
1. The steps are the same as those described in Chapter 9 for bleeding the brake system, the only difference being that the reservoir must be cleaned before starting. Note that the steps are different for vehicles equipped with ABS/ASR systems. When bleeding a section of the brake system, allow the old brake fluid to drain out.
2. Following the procedure in Chapter 9, first open the first bleed valve and gently pump the brake pedal until almost all of the old fluid has drained from the master cylinder reservoir.
3. Add new fluid to the "MAX" mark, and continue pumping the pedal until only new fluid remains in the reservoir and new fluid appears from under the valve. Close the valve and add fluid to the "MAX" mark on the reservoir.
4. Perform a similar operation sequentially with all valves of the system. Maintain the fluid level in the master cylinder reservoir not below the "MIN" mark. If this is not done, air may enter the system and this will significantly increase the duration of the operation.
Advice: The color of the old fluid is much darker than the new one. This circumstance allows you to easily distinguish the fluid.
[Article obtained from this portal MercedesMan.ru]
5. After completing the operation, check that all valves are tightened and have dust caps on them. Wipe off all traces of fluid leaks and check the fluid level in the master cylinder reservoir.
6. Before driving the car on the road, check the operation of the brakes.