1955-57 Power Brake Pedal Conversion

When a classic car was equipped with factory power brakes (Treadle-Vac), the brake pedal was twice as large as the non-power brake pedal. The large brake pedal has "POWER BRAKE" imprinted on the face of it. This larger pedal tells everyone you have power brakes, and it just looks cool. When installing an aftermarket brake booster on a Tri-Five car, a non-power brake assembly must be used, giving you the smaller brake pedal. The Treadle-Vac brake swing arm, which has the larger brake pedal, is tough to find and will not work with the aftermarket brake booster. Classic Chevy has now developed a formed bolt-on kit that will allow the use of the larger brake pedal on a non-power brake swing arm.

Parts List

• 57-176425-1 1955-57 Power Brake Pedal Conversion Kit
• 57-132459-1 1955-57 Brake Pedal Bushings

Tools Needed

• Drill and 1/4" Drill Bit
• 7/16" Wrench
• C-Clamp

Time Frame:

• 1 hour

Instructions

Image 1: When installing an aftermarket brake booster like our PIN 57-132416-1 on a Tri-Five car, the non-power brake assembly must be used. The non-power brake has the smaller pedal, which is the same size as the clutch pedal.

Image 2: If the car had factory power brakes, the brake pedal was twice as big and had the words "Power Brake" imprinted on it.

Image 3a, 3b: The Brake Pedal swing arm assembly does not need to be removed to install the new brake conversion, but our swing arm needs new upper bushings so we will remove ours. The swing arm has a steel sleeve attached to the swing arm support under the dash with a 5/16" X 3/4" bolt, nut, and lock washer. With this bolt removed, the sleeve and brake arm can be removed from the support.

Image 4: The brake ratio is different between non-power and power brakes. To achieve the correct brake ratio and travel, a new 3/8" hole must be drilled 1" lower than the original hole in the arm.

Image 5a, 5b: The brake conversion kit is designed to be bolted in but can be welded if you wish. The kit includes the large brake pedal rubber, the steel pedal, and mounting hardware. The mounting is curved to match the contour of the original.

Image 6a, 6b: The holes in the new pedal are offset slightly to move the pedal to the left of the steering column, allowing for more brake to gas clearance. Clamp the pedal in place and, using the holes in the pedal, drill two 1/4" holes through the original brake arm.

Image 7a, 7b: Using the supplied 1/4" carriage bolts, nuts, and lock washers, bolt the new pedal to the original arm. Here you can see the slight offset in the new pedal.

Image 8: The PN 57-132459-1 bushings at the top of the brake swing arm simply push in.

Image 9a, 9b: Now simply install the new rubber on the new large brake pedal and reinstall the swing arm. Now the car will have a factory power brake and look super!