A hydraulic brake system of a motor vehicle includes a linear actuator as a driver-independent pressure provision device and a hydraulic valve arrangement between the linear actuator and wheel brakes. In the case of a reduced availability of the linear actuator, a holding mode is carried out, in which the hydraulic pressure in the wheel brakes is shut in with the valve arrangement and a power output of the linear actuator is reduced, the system pressure gradient in the holding mode is measured, and a transition from the holding mode into an alternative mode is carried out based on the system pressure gradient.

A brake system for a motor vehicle includes separate first and second brake circuits associated to first and second vehicle axles, respectively, and rigidly connected to each other. Hydraulic brake pressure is supplied by a first brake piston of a master cylinder to the first brake circuit and by a second brake piston to the second brake circuit. Operably connected to the first vehicle axle is an electric motor and operates as a recuperator, with a blending device withdrawing hydraulic fluid from the first brake circuit during a recuperation phase of the electric motor. A partition wall between the first and second brake pistons subdivides the master cylinder into a first pressure chamber associated to the first brake piston, and a separate second pressure associated to the second brake piston. A connectable and disconnectable floating piston enables a hydraulic communication between the first and second brake circuits with one another.

A brake control device includes: a liquid pressure line provided for each vehicle wheel and supplied with a brake liquid pressure; a pressurization unit configured to supply a pressurization brake liquid pressure to the liquid pressure line; an abnormality detection unit configured to detect an abnormality of the liquid pressure line at a time the brake liquid pressure of the liquid pressure line is not greater than a threshold value; and a pressurization adjustment unit configured to continuously supply the pressurization brake liquid pressure to the liquid pressure line of the normal vehicle wheel having a low abnormality occurrence risk and suppress the supply pressure of the pressurization brake liquid pressure to the liquid pressure line of the vehicle wheel having a high abnormality occurrence risk until the abnormality of the liquid pressure line is detected by the abnormality detection unit.

The invention relates to an air-actuated vehicle system, comprising an actuating device which houses a pressurizable chamber, a pressurized air source, a conduit extending between the pressurized air source and the actuating device, for enabling the pressurizable chamber of the actuating device to be pressurized with air from the pressurized air source, and a pressure sensing arrangement measuring a first pressure inside the pressurized air source and a second pressure inside the pressurizable chamber, wherein the pressure sensing arrangement is configured to determine that the system has an air leakage when the result of the measurement(s) of said second pressure deviates from an expected result, wherein the expected result is based on the result of the measurement(s) of said first pressure. The invention also relates to a method of leakage detection.

A system and method for wireless digital air brake testing, the system including: at least two hand held units, a control unit including a user interface, at least two end of train air brake units, and an air manifold connected to the at least two end of train air brake units. The system and method further include electronics connecting the user interface to the air manifold to selectively supply air to selected end of train air brake units, and at least one hand held unit wirelessly connected to the electronics to also selectively supply air to selected end of train air brake units.

An automatic braking system of a vehicle includes an auxiliary braking device at at least two wheels of the vehicle. A controller is operable to control the auxiliary braking devices responsive to an input from a brake fluid pressure sensor and an input from a brake pedal position sensor. Responsive to the inputs being indicative of a brake pedal of the vehicle being applied and a brake fluid pressure of brake fluid of a hydraulic brake system of the vehicle being below a threshold level for the degree of application of the brake pedal, the controller determines that there is at least a partial failure of the hydraulic brake system of the vehicle and controls the auxiliary braking devices to slow down the vehicle.

A method for determining a leakage in a hydraulic brake system in a vehicle includes evaluating a suspected leakage in the hydraulic brake system and taking into account an actuation of an automated hand brake during the evaluation of the suspected leakage. The hydraulic brake system has a hydraulic footbrake and the automated hand brake has an electromechanical actuator. The hydraulic footbrake and the automated hand brake are configured to act on the same brake piston.

A method of detecting a leak in a hydraulic trailer brake circuit of a trailer includes providing a controller, a base valve, a first sensor, a second sensor, a control valve having a solenoid, a reduction valve, a hydraulic fluid supply, a first brake output, and a second brake output. The method also includes supplying a first pressure to an inlet of the base valve and outputting a second pressure from an outlet of the base valve to the first brake output. The first pressure is detected by the first sensor and the second pressure is detected by the second sensor, and the detected first and second pressures are communicated to the controller. The difference between the first and second pressures are compared to a threshold, and a leak is detected in the hydraulic trailer brake circuit if the difference satisfies the threshold.

A method of detecting a leak in an air trailer brake circuit of a trailer includes providing a controller, a base valve, a first sensor, a second sensor, a leak control valve having a solenoid, a pneumatic fluid supply, a first brake output, and a second brake output. The method further includes supplying a first pressure to an inlet of the base valve and outputting a second pressure from an outlet of the base valve. The first pressure is detected with the first sensor and the second pressure is detected with the second sensor. The method also includes communicating the detected first pressure and the second pressure to the controller, and comparing a difference between first pressure and the second pressure to a threshold. A leak is detected in the air trailer brake circuit if the difference satisfies the threshold.

A brake system for a motor vehicle includes separate first and second brake circuits associated to first and second vehicle axles, respectively, and rigidly connected to each other. Hydraulic brake pressure is supplied by a first brake piston of a master cylinder to the first brake circuit and by a second brake piston to the second brake circuit. Operably connected to the first vehicle axle is an electric motor and operates as a recuperator, with a blending device withdrawing hydraulic fluid from the first brake circuit during a recuperation phase of the electric motor. A partition wall between the first and second brake pistons subdivides the master cylinder into a first pressure chamber associated to the first brake piston, and a separate second pressure associated to the second brake piston. A connectable and disconnectable floating piston enables a hydraulic communication between the first and second brake circuits with one another.