Abstract: Apparatus for controlling a pneumatic brake system that includes an electronic control device to limit the maximum brake effort even when an external electrical power supply to the braking system is not present.

Abstract: A valve arrangement is disclosed for controlling the pressure in first and second brake actuation outputs (9, 10). First and second air inlet valves (1,3) supply air to respective ones of the actuation outputs; first and second exhaust valves (2,4) are each associated with a respective one of the inlet valves; and a link valve (11) is between the actuation outputs. The arrangement is such that the pressure in each of the actuation outputs is controllable selectively either in mode a) jointly, with the link valve enabling air flow between the actuation outputs or in mode b) independently, with the link valve blocking air flow between the brake actuation outputs.