Abstract: A vehicle braking system comprising a spring brake actuator having a spring brake chamber, a spring brake control assembly and an immobiliser valve which is movable between brake release position in which the spring brake control assembly is operable to cause the flow of pressurised fluid into the spring brake chamber or to vent the spring brake chamber to a low pressure region, and an immobilise position in which the spring brake control assembly is operable to connect the spring brake chamber to a low pressure region but cannot be operated to cause the flow of pressurised fluid into the spring brake chamber.

Abstract: A vehicle braking system comprising a spring brake actuator having a spring brake chamber, a spring brake control assembly and an immobiliser valve which is movable between brake release position in which the spring brake control assembly is operable to cause the flow of pressurised fluid into the spring brake chamber or to vent the spring brake chamber to a low pressure region, and an immobilise position in which the spring brake control assembly is operable to connect the spring brake chamber to a low pressure region but cannot be operated to cause the flow of pressurised fluid into the spring brake chamber.

Abstract: A vehicle braking system which includes at least one primary feature and at least one redundant feature and a braking control system which is operable to determine whether a predetermined condition, which is not indicative of failure of the primary feature or the redundant feature, is met, wherein if the predetermined condition is met, the braking control system causes the primary feature to be operable and if the predetermined condition is not met, the braking control system causes the redundant feature to be operable.

Abstract: A vehicle braking system comprising a spring brake actuator having a spring brake chamber, a spring brake control assembly and an immobiliser valve which is movable between brake release position in which the spring brake control assembly is operable to cause the flow of pressurised fluid into the spring brake chamber or to vent the spring brake chamber to a low pressure region, and an immobilise position in which the spring brake control assembly is operable to connect the spring brake chamber to a low pressure region but cannot be operated to cause the flow of pressurised fluid into the spring brake chamber.

Abstract: A method of vehicle stability control including the steps of: a) applying a test braking pulse to a wheel on a first side of the vehicle and to a wheel on a second, opposite, side of the vehicle, b) measuring the rotational speed of both wheels during the test braking pulse, c) calculating a change in wheel speed during the test braking pulse for each wheel, d) calculating the difference between the change in speed of the wheels, e) carrying out a stability control intervention if the difference exceeds a predetermined threshold, f)ceasing the test braking pulse if the difference over the first period of times is less than a predetermined level, and g) continuing the test braking pulse for a second period of time if the difference over the first period of time is greater than the predetermined level.

Abstract: A vehicle braking system includes a brake actuator, a braking control valve assembly and an emergency apply valve having a control port which is connected to the supply line by a further control line. The braking system also includes an electrically operable brake apply valve that is movable between a first position in which fluid flow along the further control line is permitted and a second position in which fluid flow along the further control line is substantially prevented and the control of the emergency apply valve is connected to a low pressure region.

Abstract: A method of vehicle stability control including the steps of: a) applying a test braking pulse to a wheel on a first side of the vehicle and to a wheel on a second, opposite, side of the vehicle, the application of the test braking pulse comprising operating a brake actuator to apply a low level braking pressure to the wheel, b) measuring the rotational speed of both wheels during the test braking pulse, c) calculating a change in wheel speed during the test braking pulse for each wheel, d) calculating the difference between the change in speed of the wheel at the first side of the vehicle and the change in speed of the wheel at the second side of the vehicle, e) carrying out a stability control intervention if the said difference exceeds a predetermined threshold.

Abstract: A vehicle braking system includes a brake actuator, a braking control valve assembly and an emergency apply valve having a control port which is connected to the supply line by a further control line. The braking system also includes an electrically operable brake apply valve that is movable between a first position in which fluid flow along further control line is permitted and a second position in which fluid flow along the further control line is substantially prevented and the control of the emergency apply valve is connected to a low pressure region.

Abstract: A method of operating a braking system for a trailer (16) having at least one axle on which are mounted two ground-engaging wheels (26, 26?, 28, 28?), one of which is provided on a first side of the trailer (16) whilst the other is provided on a second side of the trailer (16), each wheel (26, 26?, 28, 28?) having a brake which is operable independently of the other by means of a brake actuator assembly (26b, 26b?, 28b, 28b?, 46, 46?), the method including controlling the difference between the brake pressure applied by the brake to the wheel (26, 28) on the first side of the trailer (16) and the brake pressure applied by the brake to the wheel (26?, 28?) on the second side of the trailer (16) so that it does not exceed a predetermined maximum pressure differential.