An air disc brake for a road vehicle is proposed, having a mechanism for causing retraction of the brake pads when the brakes are no longer applied, to avoid parasitic drag caused by continued contact of the brake pads against the brake disc. The proposed mechanism includes a pin located in a fixed position relative to one brake pad, and extending through an aperture in the other brake pad. A coil spring is supported on the pin, and pushes the brake pads apart. Where the pin extends through the aperture the extent of the pin provides an indication of the wear state of the pads and disc, which is visible through apertures in the wheel rim.

An air disc brake for a road vehicle is proposed, having a mechanism for causing retraction of the brake pads when the brakes are no longer applied, to avoid parasitic drag caused by continued contact of the brake pads against the brake disc. The proposed mechanism includes a pin located in a fixed position relative to one brake pad, and extending through an aperture in the other brake pad. A coil spring is supported on the pin, and pushes the brake pads apart. Where the pin extends through the aperture the extent of the pin provides an indication of the wear state of the pads and disc, which is visible through apertures in the wheel rim.

Via a method for venting at least one brake channel in a brake circuit of a compressed-air brake system of a vehicle, the brake channel can be vented. The compressed-air brake system has a brake pressure modulator that includes switchable valves for a control pressure. The brake system has an electronic control device interacting with the modulator. The modulator has, for each brake channel, at least one relay valve via which, firstly, a quantity of air can be introduced into at least one brake cylinder for actuating the brake and, secondly, the brake cylinder can be vented. During the venting operation, an adjustment to a setpoint pressure target is implemented. A setpoint pressure gradient during the venting operation is changed, in a manner dependent upon the pressure in the brake cylinder and on the operating state of the vehicle, in accordance with an algorithm stored in the control unit.

Via a method for venting at least one brake channel in a brake circuit of a compressed-air brake system of a vehicle, the brake channel can be vented. The compressed-air brake system has a brake pressure modulator that includes switchable valves for a control pressure. The brake system has an electronic control device interacting with the modulator. The modulator has, for each brake channel, at least one relay valve via which, firstly, a quantity of air can be introduced into at least one brake cylinder for actuating the brake and, secondly, the brake cylinder can be vented. During the venting operation, an adjustment to a setpoint pressure target is implemented. A setpoint pressure gradient during the venting operation is changed, in a manner dependent upon the pressure in the brake cylinder and on the operating state of the vehicle, in accordance with an algorithm stored in the control unit.

A trailer ABS system is provided with an ABS valve in which pressure to the control chamber is switchable by a 2/2 solenoid valve, the solenoid valve being switchable between a first position in which the control chamber is pressurized by the control pressure and a second position, in which the control chamber is connected to the exhaust. The braking ECU is operable to actuate the solenoid between the first and second positions to thereby provide ABS functionality.

A trailer ABS system is provided with an ABS valve in which pressure to the control chamber is switchable by a 2/2 solenoid valve, the solenoid valve being switchable between a first position in which the control chamber is pressurized by the control pressure and a second position, in which the control chamber is connected to the exhaust. The braking ECU is operable to actuate the solenoid between the first and second positions to thereby provide ABS functionality.

A pneumatic brake cylinder of a vehicle brake has a brake cylinder housing, a brake piston guided axially in the brake cylinder housing with an extendable and retractable piston rod, which projects through an opening in a bottom of the brake cylinder housing, and a brake chamber which can be ventilated and exhausted. A fastening device is provided for the detachable fastening of the brake cylinder to a support structure for the brake cylinder, and includes at least one fastening bolt projecting away from the brake cylinder housing in the region of the bottom. A venting device interacts with the return spring chamber such that, in the event of a change in the volume of the return spring chamber as a result of a movement of the brake piston, air can pass out of the return spring chamber or into the return spring chamber by the venting device. The ventilation device includes the at least one fastening bolt which has at least one internal channel which opens, on the one hand, with a first mouth into the return spring chamber and, on the other hand, with a second mouth into an outer area of the brake cylinder.

A pneumatic brake cylinder of a vehicle brake has a brake cylinder housing, a brake piston guided axially in the brake cylinder housing with an extendable and retractable piston rod, which projects through an opening in a bottom of the brake cylinder housing, and a brake chamber which can be ventilated and exhausted. A fastening device is provided for the detachable fastening of the brake cylinder to a support structure for the brake cylinder, and includes at least one fastening bolt projecting away from the brake cylinder housing in the region of the bottom. A venting device interacts with the return spring chamber such that, in the event of a change in the volume of the return spring chamber as a result of a movement of the brake piston, air can pass out of the return spring chamber or into the return spring chamber by the venting device. The ventilation device includes the at least one fastening bolt which has at least one internal channel which opens, on the one hand, with a first mouth into the return spring chamber and, on the other hand, with a second mouth into an outer area of the brake cylinder.

A hydraulic system includes a pump having a pump outlet, a tank configured to supply fluid to the pump, a hydraulic motor coupled to an air compressor that is configured to supply compressed air to an air brake, a steering gear having an inlet workport and an outlet workport, and a compressor bypass valve. The compressor bypass valve is selectively movable between a first position where fluid flow is provided from the pump outlet to both the hydraulic motor and the inlet workport of the steering gear and a second position where the fluid flow from the pump outlet bypasses the hydraulic motor and is supplied to the inlet workport of the steering gear.

A hydraulic system includes a pump having a pump outlet, a tank configured to supply fluid to the pump, a hydraulic motor coupled to an air compressor that is configured to supply compressed air to an air brake, a steering gear having an inlet workport and an outlet workport, and a compressor bypass valve. The compressor bypass valve is selectively movable between a first position where fluid flow is provided from the pump outlet to both the hydraulic motor and the inlet workport of the steering gear and a second position where the fluid flow from the pump outlet bypasses the hydraulic motor and is supplied to the inlet workport of the steering gear.