1955-57 power brake pedal conversion - Eckler's Classic Chevy

y Randy Irwin1955-57 POWER BRAKE PEDAL CONVERSIONRandy Irwin - Technical WriterRandy has been involved in the Chevyparts business for over 25 years. He is a wizardat creating, making and modifying customparts for Chevys.When a classic was equipped with factory power brakes (Treadle-Vac)the power brake pedal pad was twice as large as the non-power brakepedal pad. The large pedal pad has “POWER BRAKE” imprinted on theface of the pad. This larger pedal pad tells everyone you have powerbrakes and it just looks cool. When installing an aftermarket power brakebooster on a Tri-Five, a non-power brake pedal assembly must be used,giving you the smaller pedal pad. The Treadle-Vac brake pedal swing armwhich has the larger pedal pad is tough to find and will not work with theaftermarket brake booster. Classic Chevy has now developed a formedbolt-on plate that will allow the use of the larger power brake pedal pad ona non-power brake pedal swing arm.Photo #1: Wheninstalling an aftermarketpower brake booster likeour P/N 20-57 on a Tri-Five car the non-powerbrake pedal assemblymust be used. The nonpowerbrake pedal hasthe small pedal padwhich is the same size asthe clutch pedal pad.Photo #2: If the carhad factory powerbrakes the brakepedal pad was twiceas big and had thewords “Power Brake” imprinted on the pad.20-160#3a #3b20-97Parts Needed:20-160 55-57 Power Brake Pedal Conversion20-97 55-57 Brake Pedal BushingsTo order parts call 1-800-456-1957 or visit ClassicChevy.comPhoto #3a & 3b: The brake pedalswing arm assembly does not need to be removed to install thenew power brake pedal conversion, but our swing arm needsnew upper bushings so we will remove ours. The swing armpivots on a steel sleeve attached to the swing arm supportunder the dash with a 5/16” X 3/4” bolt, nut and lock washer.With this bolt removed, the pivot sleeve and brake pedal armcan be removed from the support.Tools Needed:Drill and 1/4” Drill Bit7/16” WrenchC-ClampTime Frame:1 HourPhoto #4: The brakepedal ratio is differentbetween non-power andpower brakes. To achievethe proper brake pedalratio and pedal travel, anew 3/8” hole must bedrilled 1” lower than theoriginal hole in the arm.

#5a #5bPhoto #8: The P/N20-97 bushings atthe top of thebrake pedal swingarm simply press inplace.Photo #5a & 5b: The power brake pedal conversion kit isdesigned to be bolted in place, but can be welded if you wish.The kit includes the large power brake rubber pad, the steelpedal plate and mounting hardware. The mounting plate iscurved to match the contour of the original pedal plate.#6a#6cPhoto #9a & 9b: Now simply install the new rubber pad on thenew large pedal plate and reinstall the swing arm. Now the carwill have a factory power brake pedal pad and look super!Good Luck!#6bPhoto #6a & 6b & 6c: Theholes in the new plate areoffset slightly to move thepedal to the left of thesteering column allowingfor more brake pedal to gaspedal clearance. Clamp thepedal plate in place andusing the holes in the plate,drill two 1/4” holes throughthe original brake pedalplate.#7a #7bPhoto #7a & 7b: Using the supplied 1/4” carriage bolts, nutsand lock washers, bolt the new plate to the original pedal plate.Here you can see the slight offset in the new pedal plate.