Bleeding the brake system using a special device
1, 2 — Rear brake calipers
3, 4 — Front brake calipers
After repairing the brake system, during which its hydraulic tract was opened, air may get inside the latter, which must then be completely removed. A sign of the presence of air in the working circuits of the brake system is the softness of the brake pedal.
Note: If air enters the system as a result of a leak, the cause of the malfunction must first be eliminated.
If air gets into a single wheel cylinder, it is sufficient to bleed only the corresponding support. If air gets into the system tract as a result of excessive lowering of the fluid level in the master cylinder reservoir, as well as after removal/installation of the latter, the entire system is bled. The same applies to the case of performing maintenance procedures that require dismantling the hydraulic modulator.
Air is removed from the hydraulic tract of the brake system using a special device, the connection of which must be carried out in strict accordance with the manufacturer's instructions - the procedure should be entrusted to car service specialists.
Note: The pumping pressure is 2 atm.
Information copied from the website (www.MercedesMan.ru)