Abstract: In order to detect air in a brake master cylinder within a hydraulic power brake system, a brake master cylinder pressure on actuation of the brake master cylinder is compared with a comparison pressure which prevails in the brake master cylinder when it is air-free. For bleeding, brake fluid is conveyed with a power brake pressure generator through the in this case non-actuated brake master cylinder into a pressureless brake fluid reservoir, where air escapes from the brake fluid.

Abstract: For testing the functional capability of a hydraulic power vehicle braking system, a power brake pressure generator is switched on. The power brake pressure generator displaces brake fluid through the non-actuated master brake cylinder into a brake fluid reservoir, which is why no brake pressure is built up. A brake pressure build-up allows a “hidden defect” to be inferred, which has no impact during normal operation and is therefore not noticed.

Abstract: To prevent the loss of any brake fluid from a hydraulic vehicle braking system after a detected leakage, a testing or a re-testing of a leak tightness of the vehicle braking system is carried out only after release, for example, after a repair of the vehicle braking system.

Abstract: A method for decreasing brake-pressure of an electronically slip-controllable power braking system (ESPBS) and an ESPBS. The wheel-brake pressure is generated by electronic activation of a drive motor (DM) of a pressure generator (PG) (external force). The driver indicates braking intention by actuating a master brake cylinder, which is set indirectly by a control unit via electronic activation of the DM. Plunger devices (PDs) include a plunger piston (PP), accommodated moveably in a plunger cylinder (PC). Driven by the DM, PP and PC execute a translational movement in relation to one another. A pressure buildup/decrease is performable in a BC connected to the PD as a function of movement direction. To avoid pressure medium contaminated with gas entering the BC undetected during pressure decrease after cancellation of the intention, actuation of the PD in the pressure-decrease direction is performed until the BC pressure has dropped to a pre-determinable threshold and ended.

Abstract: To test a vehicle power braking system, a piston of a power brake pressure generator is displaced twice for a pressure build-up and in between back preferably by a longer distance. Extension of the piston travel during the second displacement is an indication of air in a cylinder of the power brake pressure generator due to an excessively low brake fluid level in a brake fluid reservoir.

Abstract: A method for decreasing brake-pressure of an electronically slip-controllable power braking system (ESPBS) and an ESPBS. The wheel-brake pressure is generated by electronic activation of a drive motor (DM) of a pressure generator (PG) (external force). The driver indicates braking intention by actuating a master brake cylinder, which is set indirectly by a control unit via electronic activation of the DM. Plunger devices (PDs) include a plunger piston (PP), accommodated moveably in a plunger cylinder (PC). Driven by the DM, PP and PC execute a translational movement in relation to one another. A pressure buildup/decrease is performable in a BC connected to the PD as a function of movement direction. To avoid pressure medium contaminated with gas entering the BC undetected during pressure decrease after cancellation of the intention, actuation of the PD in the pressure-decrease direction is performed until the BC pressure has dropped to a pre-determinable threshold and ended.

Abstract: To test a vehicle power braking system, a piston of a power brake pressure generator is displaced twice for a pressure build-up and in between back preferably by a longer distance. Extension of the piston travel during the second displacement is an indication of air in a cylinder of the power brake pressure generator due to an excessively low brake fluid level in a brake fluid reservoir.