A brake system comprising: a control system, an operator input device and a plurality of brakes (15, 16, 17, 18); and a brake valve assembly comprising at least one channel (31, 35, 71, 75) comprising: an operator brake valve (32, 36, 72, 76) controllable by the operator input device; and an automatic brake valve (33, 37, 71, 75) controllable by the control system; characterised by a control valve (34, 38, 74, 78) fluidly connected to at least one brake of the plurality of brakes (15, 16, 17, 18) and the operator and automatic brake valves (32, 36, 72, 76, 33, 37, 71, 75), wherein the control valve (34, 38, 74, 78) is configurable by the control system between an operator brake configuration for fluidly connecting the operator brake valve (32, 36, 72, 76) to the at least one brake (15, 16, 17, 18) and an automatic brake configuration for fluidly connecting the automatic brake valve (33, 37, 71, 75) to the at least one brake (15, 16, 17, 18); wherein the brake valve assembly is configurable in: an operator braking mode in which the control valve (34, 38, 74, 78) is in the operator brake configuration and the at least one brake (15, 16, 17, 18) is controllable by the operator brake valve (32, 36, 72, 76) in response to an input to the operator input device; and an automatic braking mode in which the control valve (34, 38, 74, 78) is in the automatic brake configuration and the at least one brake (15, 16, 17, 18) is controllable by the automatic brake valve (33, 37, 71, 75) in response to a control signal from the control system. a control system, an operator input device and a plurality of brakes (15, 16, 17, 18); and a brake valve assembly comprising at least one channel (31, 35, 71, 75) comprising: an operator brake valve (32, 36, 72, 76) controllable by the operator input device; and an automatic brake valve (33, 37, 71, 75) controllable by the control system; characterised by a control valve (34, 38, 74, 78) fluidly connected to at least one brake of the plurality of brakes (15, 16, 17, 18) and the operator and automatic brake valves (32, 36, 72, 76, 33, 37, 71, 75), wherein the control valve (34, 38, 74, 78) is configurable by the control system between an operator brake configuration for fluidly connecting the operator brake valve (32, 36, 72, 76) to the at least one brake (15, 16, 17, 18) and an automatic brake configuration for fluidly connecting the automatic brake valve (33, 37, 71, 75) to the at least one brake (15, 16, 17, 18); wherein the brake valve assembly is configurable in: an operator braking mode in which the control valve (34, 38, 74, 78) is in the operator brake configuration and the at least one brake (15, 16, 17, 18) is controllable by the operator brake valve (32, 36, 72, 76) in response to an input to the operator input device; and an automatic braking mode in which the control valve (34, 38, 74, 78) is in the automatic brake configuration and the at least one brake (15, 16, 17, 18) is controllable by the automatic brake valve (33, 37, 71, 75) in response to a control signal from the control system. an operator brake valve (32, 36, 72, 76) controllable by the operator input device; and an automatic brake valve (33, 37, 71, 75) controllable by the control system; characterised by a control valve (34, 38, 74, 78) fluidly connected to at least one brake of the plurality of brakes (15, 16, 17, 18) and the operator and automatic brake valves (32, 36, 72, 76, 33, 37, 71, 75), wherein the control valve (34, 38, 74, 78) is configurable by the control system between an operator brake configuration for fluidly connecting the operator brake valve (32, 36, 72, 76) to the at least one brake (15, 16, 17, 18) and an automatic brake configuration for fluidly connecting the automatic brake valve (33, 37, 71, 75) to the at least one brake (15, 16, 17, 18); wherein the brake valve assembly is configurable in: an operator braking mode in which the control valve (34, 38, 74, 78) is in the operator brake configuration and the at least one brake (15, 16, 17, 18) is controllable by the operator brake valve (32, 36, 72, 76) in response to an input to the operator input device; and an automatic braking mode in which the control valve (34, 38, 74, 78) is in the automatic brake configuration and the at least one brake (15, 16, 17, 18) is controllable by the automatic brake valve (33, 37, 71, 75) in response to a control signal from the control system. an operator braking mode in which the control valve (34, 38, 74, 78) is in the operator brake configuration and the at least one brake (15, 16, 17, 18) is controllable by the operator brake valve (32, 36, 72, 76) in response to an input to the operator input device; and an automatic braking mode in which the control valve (34, 38, 74, 78) is in the automatic brake configuration and the at least one brake (15, 16, 17, 18) is controllable by the automatic brake valve (33, 37, 71, 75) in response to a control signal from the control system.