A device for separating brake dust and particles, for collecting dust and particles produced by one or more pads of a brake assembly, the device comprising: - a casing having an inlet for admitting a flow of air laden with brake dust and particles, and an outlet (8; 36) for discharging purified air, the casing comprising a tubular lateral wall extending around a longitudinal axis and an end wall, - separation means, spaced axially away from the end wall to retain at least some of the brake dust and particles admitted via the inlet, - a trapping zone for trapping the dust and particles separated by the separation means, and - a downstream zone delimited by the separation means in the casing, the downstream zone being situated, at least in part, axially at the opposite end from the inlet and/or from the trapping zone, characterized in that the separation means comprise a group of cyclones, housed in the casing and able to separate dust and particles, as well as water droplets present in the flow of air admitted via the inlet, each of the cyclones comprising a body that tapers in downward direction, having a lower end opening via a gravity discharge orifice into said trapping zone, said body delimiting a separation chamber, the group comprising: - an axial supply inlet common to the cyclones of the group, and provided with a connector for an axial duct allowing the flow of air admitted via the inlet to circulate as far as the group of cyclones from beneath; - a plurality of exhaust stacks each discharging air from a separation chamber and opening into the downstream zone inside the casing; and - an intake manifold having a plurality of tubular branches to distribute said flow of air laden with dust and particles, extending between the axial supply inlet and each respective separation chamber of the cyclones, each of the tubular branches opening radially into a corresponding separation chamber, all the bodies of the cyclones being placed radially distant from the longitudinal axis, between the longitudinal axis and the lateral wall; and in that the group of cyclones forms a transverse barrier connected in a fluidtight manner to the axial duct, the transverse barrier and the axial duct preventing a heterogeneous liquid-solid mixture from traveling back up toward the downstream zone during operation of the device. - a casing having an inlet for admitting a flow of air laden with brake dust and particles, and an outlet (8; 36) for discharging purified air, the casing comprising a tubular lateral wall extending around a longitudinal axis and an end wall, - separation means, spaced axially away from the end wall to retain at least some of the brake dust and particles admitted via the inlet, - a trapping zone for trapping the dust and particles separated by the separation means, and - a downstream zone delimited by the separation means in the casing, the downstream zone being situated, at least in part, axially at the opposite end from the inlet and/or from the trapping zone, - an axial supply inlet common to the cyclones of the group, and provided with a connector for an axial duct allowing the flow of air admitted via the inlet to circulate as far as the group of cyclones from beneath; - a plurality of exhaust stacks each discharging air from a separation chamber and opening into the downstream zone inside the casing; and - an intake manifold having a plurality of tubular branches to distribute said flow of air laden with dust and particles, extending between the axial supply inlet and each respective separation chamber of the cyclones, each of the tubular branches opening radially into a corresponding separation chamber, all the bodies of the cyclones being placed radially distant from the longitudinal axis, between the longitudinal axis and the lateral wall;