A brake system includes a service brake and a parking brake that brake a vehicle including a lift axle capable of ascending and descending. The brake system further includes a brake blocker device and a controller that controls the brake blocker device. The brake blocker device blocks at least one of supply of compressed air to the service brake and supply of compressed air to the parking brake. The service brake and the parking brake act on the lift axle. The controller actuates the brake blocker device when the lift axle is at a lifted position.

A control apparatus is configured to control a brake of a unit hauled by a vehicle. The vehicle includes a plurality of brakes for braking the wheels of the vehicle, a trailer brake for braking the hauled unit, and a parking brake for keeping the vehicle braked while it is stationary. The control apparatus includes a line for sending a fluid to the trailer brake through a control valve in order to brake the hauled unit in certain working conditions, a further line for sending a further fluid to the trailer brake in order to activate the trailer brake in other working conditions, and a valve device for controlling flow of the further fluid in the further line, the valve device being responsive to a signal indicative of the status of the parking brake.

A storage arrangement for lines from a tractor truck to a trailer including an electrical line, a first pneumatic line and a second pneumatic line includes a housing member configured to be secured to the truck, first, second and third receivers connected to the housing and configured to couple to the electrical and pneumatic lines and a control arrangement operably coupled to the receivers such that upon coupling of the lines with the receivers the control arrangement and engagement of parking brakes of the trailer allows an operator to unlock a kingpin from a fifth wheel hitch plate assembly, wherein the control arrangement prevents the operator from unlocking the kingpin from the fifth wheel hitch plate assembly prior to the lines being coupled with the receivers and engagement of the parking brakes.

A trailer control valve for controlling a hydraulic dual-line brake system of a trailer vehicle has an inlet for a hydraulic supply line of the towing vehicle, a tank outlet for an unpressurized return-flow line of the towing vehicle, a brake pressure outlet, and a supplemental pressure outlet. The brake pressure outlet can be connected in a stepped manner with an electronically controlled brake control valve to the supply pressure inlet or to the tank outlet. The supplemental pressure outlet can connect using a valve arrangement so that an outlet pressure of the supply pressure is reduced to a supplemental pressure at the supply pressure inlet or at the tank outlet. The valve arrangement has a pressure-limiting valve and a shut-off valve arranged in series. The shut-off valve can be a 3/2-way valve, which when not energized, the supplemental pressure outlet is connected to the tank outlet.