Primary circuit: In the DSC hydraulic control unit, air bubbles can adhere to the edges and valves, and these cannot be removed by rinsing with the brake fluid change unit. The vibrations that occur during ventilation with the diagnosis system loosen the air bubbles. Secondary circuit: Under normal conditions (DSC does not intervene), the secondary circuit of the DSC hydraulic control unit is closed, so that the air it contains cannot escape when rinsing with the brake fluid change unit. When bleeding with the diagnosis system, the return pump and the exhaust and high-pressure switching valves are activated during rinsing so that the secondary circuit is also bled. After the exchange and repair of the following components, bleeding must be done with the diagnosis system: - Hydraulic unit - Master Brake Cylinder - Components or connection lines that are located between the hydraulic unit and tandem brake master cylinder Operations: For the DSC8, the operations 3 ... 7 must be performed in the order rear right, rear left, front right and front left. For the DSC Mk60 the operations are specified explicitly in the test module. Connect the brake fluid-change unit and switch on (the filling pressure must not exceed 2 bar) Fully rinse the brake system Attach the bleeder container to the vent valve Open vent valve Start bleeding with the diagnosis system with open vent valve After completing the bleeding, operate the brake pedal 5 times to the limit position; bubble-free brake fluid must escape Close vent valve Remove the brake fluid change unit Note: A second person is required for this task