A motor vehicle brake system having at least four hydraulically actuatable wheel brakes, including an electrically actuatable inlet valve for each wheel brake. A master brake cylinder actuable by a brake pedal is separably hydraulically connected via an isolation valve to a brake supply line to which the inlet valves are connected, and an electrically controllable pressure-providing device having a pressure space hydraulically connected to the brake supply line. An electrically actuatable circuit isolation valve inline with the brake supply line. With the circuit isolation valve closed the brake supply line is hydraulically separated into first and second line sections. The first line section connected to two of the inlet valves, and the second line section connected to the remaining inlet valves. The pressure space is hydraulically connected to the second line section. The circuit isolation valve is normally open, wherein the pressure chamber of the master brake cylinder is connected to the first line section via the isolation valve.

A controller on a tractor portion of an articulated vehicle includes an electrical input port adapted to receive an electrical input signal based on a command to unpark a trailer portion of the articulated vehicle and an electronic processor adapted to: receive the electrical input signal from the electrical input port; identify, based on the electrical input signal, when the command to unpark the trailer is received at the electrical input port; and based on the command to unpark the trailer, transmit an electrical output signal to an electrical output port for causing supplemental compressed air to be communicated from the tractor to the trailer for filling an air tank on the trailer using a quick-fill mode.

When a leak occurs in one service circuit of a multi-circuit braking system, the leak can prevent replenishing the non-leaking service reservoir. To address this problem, a shared backup reservoir can be used to replenish the non-leaking service reservoir. A valve can be used to allow flow from the backup reservoir to whichever service reservoir is under higher pressure, as low pressure would indicate a leak. Additional valve(s) can be used to impede flow from the service reservoirs to the backup reservoir to prevent the service reservoirs from being drained if the backup reservoir is subject to a leak.

A method for detecting and isolation a leak in a hydraulic system having a supply pump serving at least one control valve is disclosed. In one embodiment, the control valve has multiple work sections. In step of the method, the hydraulic system is activated. In another step, an actuation command for at least one of the work sections is received, for example from a human-to-machine interface. Subsequently, the method may include generating a flow demand for the work sections for which an actuation command has been received. The method also includes the step of implementing at least one of a first, second, third, and fourth leak detection and isolation protocol to detect and isolate a leak between the pump and the control valve assembly, a leak between the reservoir and the control valve assembly and a leak between the at least one work circuit and the control valve assembly.

Brake fluid reservoir valve for installation in the reservoir's outlet tube. It includes an outer sleeve fixed in the reservoir tube and equipped with an outer stop and a hollow piston housed in the sleeve. The top of the piston is closed and bordered by a groove accommodating an o-ring seal that rests upon the upper edge of the sleeve whenever the piston enters the sleeve. The piston has windows beneath the groove communicating with the interior of the piston and lugs near its lower extremity. Openings are provided in the extension of the piston beneath the lugs. A compression spring is inserted between the piston and the outer sleeve, between the stop and the lugs.

A controller on a tractor portion of an articulated vehicle includes an electrical input port adapted to receive an electrical input signal based on a command to unpark a trailer portion of the articulated vehicle and an electronic processor adapted to: receive the electrical input signal from the electrical input port; identify, based on the electrical input signal, when the command to unpark the trailer is received at the electrical input port; and based on the command to unpark the trailer, transmit an electrical output signal to an electrical output port for causing supplemental compressed air to be communicated from the tractor to the trailer for filling an air tank on the trailer using a quick-fill mode.

A self-sealing hydraulic device has a connecting assembly and a hydraulic assembly. The connecting assembly has an adaptor having a shell, a male fitting, and a barb fitting. The male fitting is mounted in the shell, is axially moveable relative to the shell, and has an axial hole and a radial hole orthogonally communicating with the axial hole. The radial hole is sealed by the shell. The barb fitting is connected to and communicates with both the shell and a hose. The hydraulic assembly is assembleable to the connecting assembly and has a housing, an elastic element, and a valve unit. The housing has a hydraulic chamber and an assembling hole communicating with the hydraulic chamber via a through hole. The elastic element is disposed in the housing. The valve unit is disposed inside the hydraulic chamber and driven by the elastic element to seal the through hole.

A tractor protection valve having a parking brake supply port, a parking brake delivery port, an exhaust port, and a quick release valve positioned between the parking brake supply port and the parking brake delivery port. The quick release valve is movable between a supply position allowing fluid to flow from the parking brake supply port to the parking brake delivery port and an exhaust position allowing fluid to flow from the parking brake delivery port to the exhaust port. The quick release valve may include a diaphragm that is movable between the supply and exhaust positions. The quick release valve may include a valve body that is positioned in a housing of the tractor protection valve.

A hydraulic brake distributor comprises a first inlet (11) which may be hydraulically connected to a first brake control of a vehicle, a second inlet (16) which may be hydraulically connected to a second brake control of the vehicle, a first outlet (12) which may be hydraulically connected to a first brake of the vehicle, a second outlet (17) which may be hydraulically connected to a second brake of the vehicle, a first channel (13) which sets the first inlet (11) and the first outlet (12) in direct fluid communication, a branch channel (22) which sets the first channel (13) in fluid communication with a first internal cavity (14), and a cutoff valve (14, 18, 24) which is arranged within the first internal cavity (14) and may be actuated in response to brake fluid being sent to the second inlet (16) so as to interrupt the fluid communication through the branch channel (22).

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.