Abstract: A pressure control device for an anti-lock and/or anti-slip system of a motor vehicle comprises a valve casing (10) in which a damping chamber (36) and an expansion chamber (44) are arranged in a common recess (12, 12'), the two chambers having a common axis. A pump is disposed in an adjacent recess having an axis parallel to the common axis of the chambers whereby substantial space is saved over prior arrangements.

Abstract: A first control valve which is normally open connects a master cylinder connection to a wheel cylinder connection. A second control valve which is normally closed connects the wheel cylinder connection to a storing chamber for returning brake fluid and to an inlet passage of a return pump when it is in open position. The return pump communicates through an output passage with a damping chamber. The damping chamber is arranged in a valve receptacle for the first control valve, and the storing compartment is arranged in a valve receptacle for the second control valve.

Abstract: In an anti-lock brake system (ABS) for a motorcycle the driving stabilty is improved by measuring the position of lateral inclination of the motorcycle and adjusting at least one threshold value for the anti-skid control in response to the measurement. In another embodiment the transverse acceleration of the motor cycle is measured and an ABS threshold value adjusted accordingly.