Abstract: Am emergency braking arrangement for trucks characterized by the provision of selectively releasable brake pads typically mounted in front of the rear wheels of a truck trailer at a normal non-use condition and movable to a position beneath the truck wheels at a braking condition. The arrangement is particularly useful in controlling and/or braking the movement of a truck traveling on a downhill grade when the installed air brake system fails. The brake pads are selectively and individually controlled by the truck operator and, normally, each is restrained from unwanted movement by a plate which extends downwardly from the undersurface of the truck frame assembly. Each of the brake pads is reinforced to afford maximum durability.