30 and 32 to which upper and lower carrier guide rods 34 and 36 fig1 are secured and which also support a carrier drive screw 38 fig1 rotatably driven by an electric motor and reduction gear assembly 39 mounted on rear bracket 30 the carrier 12 is also a metal casting as shown in fig4 the carrier has a first pair of brackets 40 and 42 formed as an integral part of the carrier for pivotally supporting the brake pedal 14 fig1 and a second pair of brackets 44 and 46 also formed as an integral part of the carrier for pivotally supporting the transfer arm 16 fig1 the brackets 40 and 42 receive a pedal mounting pin 48 shown in fig3 and brackets 44 and 46 receive a pin 50 for pivotally mounting the transfer arm 16 these two pins extend at a right angle relationship to each other and accordingly the brake pedal and the transfer arm pivot about axes that are disposed at a right angle relationship the pivot axes may but do not necessarily intersect each other in the embodiment shown the pivot axis of the transfer arm is slightly higher than the pivot axis of the brake pedal again referring to fig4 the carrier 12 is provided with a rearward projection 52 at its left rear corner this projection has a straight edge 54 extending in the front to rear direction which enters guide slot 28 fig5 of the base the carrier also has.