The invention relates to a brake compensator for a hydraulic braking circuit comprising a master cylinder (10) with two working chambers respectively connected to a subcircuit (I, II), the compensator being arranged in a subcircuit (I) comprising a first piston (22) carrying a valve mechanism (24) arranged in a communication between a working chamber of the master cylinder (10) and at least one rear wheel (16) in such a way that, in the rest position, this communication is open, and a second piston (42) subjected to the pressure prevailing in the other subcircuit (II) so as to lock the first piston (22) in the rest position in the event of the absence of a substantial pressure in the other subcircuit (II). According to the invention, a ball (32) is arranged at rest on the path of the first piston (22) in order to prevent it substantially from sliding, and a displacement of the second piston (42) under the effect of a sufficient pressure prevailing in the other subcircuit (II) removes the ball at least partially from the path.