Abstract: Locking system for two brake pedals of a motor vehicle such as a tractor, for enabling joint and separate actuation of opposite wheel pairs of the type wherein a bolt is utilized to couple the pedals. In accordance with a preferred embodiment, the bolt is spring biased into a locked position and is operable by the foot of the driver so as to be shifted into an unlocked position. These positions are assumed through the use of stops that are staggered with respect to one another both radially and axially and are mounted so as to be brought into contact with a side wall of one of the pedals by rotational and axial movements of the bolt.