Abstract: A hydraulic circuit for a motor vehicle supports operation of a power steering gear and a power assisted park brake unit incorporating a spring actuated hydraulic release (SAHR) chamber. The hydraulic circuit includes a pump with the power steering gear being connected to receive hydraulic fluid under pressure from the pump. Hydraulic fluid from the pump is delivered to first and second valves, the first or release control valve being connected to the SAHR chamber and the second or recirculation valve being coupled to return hydraulic fluid to a pump inlet.

Abstract: A hydraulic circuit for a motor vehicle supports operation of a power steering gear and a power assisted park brake unit incorporating a spring actuated hydraulic release (SAHR) chamber. The hydraulic circuit includes a pump with the power steering gear being connected to receive hydraulic fluid under pressure from the pump. Hydraulic fluid from the pump is delivered to first and second valves, the first or release control valve being connected to the SAHR chamber and the second or recirculation valve being coupled to return hydraulic fluid to a pump inlet.

Abstract: A motor vehicle (12) has a chassis (16) with wheels (26, 34) on which the motor vehicle travels, a powertrain having an engine (20) coupled to at least one of the wheels, a primary brake system (38) for braking the motor vehicle via foundation brakes at the wheels, and a secondary brake system for braking the vehicle via at least one powertrain brake mechanism (57) that can apply brake torque to at least one of the wheels to which the powertrain is coupled. The primary brake system has a mechanical operator (40) that when operated by a driver causes pressure to be created in the primary brake system for operating the foundation brakes to apply brake torque correlated with magnitude of the pressure. A device (42) signals a controller (44) that the foundation brakes are being applied. A selector (58) available to the driver signals the controller for selectively enabling use of the secondary brake system in conjunction with the primary brake system.

Abstract: An automatically adjustable fifth wheel assembly for a vehicle and trailer combination that adjusts the position of the trailer relative to the vehicle is provided.

Abstract: A vehicle has at least one road wheel on which the vehicle travels and a park brake for selectively locking the at least one road wheel while the vehicle is parked. An actuator can apply the park brake to lock the at least one road wheel, and can release the park brake to unlock the at least one road wheel. An electronic controller interfaces the actuator with a wheel locking mechanism. The status of a variable status device, such as a lift platform, is communicated to the electronic controller and is effective on the electronic controller for causing the electronic controller to disallow park brake release by the actuator when a first status is communicated to the electronic controller and to allow park brake release by the actuator when a second status is communicated to the electronic controller.

Abstract: A motor vehicle (12) has a chassis (16) with wheels (26, 34) on which the motor vehicle travels, a powertrain having an engine (20) coupled to at least one of the wheels, a primary brake system (38) for braking the motor vehicle via foundation brakes at the wheels, and a secondary brake system for braking the vehicle via at least one powertrain brake mechanism (57) that can apply brake torque to at least one of the wheels to which the powertrain is coupled. The primary brake system has a mechanical operator (40) that when operated by a driver causes pressure to be created in the primary brake system for operating the foundation brakes to apply brake torque correlated with magnitude of the pressure. A device (42) signals a controller (44) that the foundation brakes are being applied. A selector (58) available to the driver signals the controller for selectively enabling use of the secondary brake system in conjunction with the primary brake system.