Norton Service Release Database N74

SERVICE RELEASE N74

NATURE OF RELEASE: Front drum brake- high proformance modification MODELS AFFECTED: All Commando PARTS AFFECTED: Front brake plate and shoes assembly DISTRIBUTION: Worldwide (Trade only) EXPLANATION: To stiffen up the two leading shoe front brake assembly, thereby providing an appreciable improvement in braking figures for high performance purposes, a support plate is introduced. The support plate ties in a precise relationship between both brake cams and pivot pins. The support plate is shown in the illustration, in situ. The parts required to convert an existing brake are available in kit, Part No. 063410, comprising:-   ACTION: To convert an existing brake plate, remove the brake shoes and springs, the brake expander cams and both pivot pins. To remove the short pivot pin, first support the brake plate firmly and squarely under a drilling machine and gently remove the rivetted shoulder of the fixed pivot pin. Final detachment of the stop pin may necissitate heating the brake plate by immersing in boiling water before driving or pressing out. Retain the chamfered washer. Replace the new pivot pin by pressing into the brake plate pin housing and supporting the brake plate and new pivot pin firmly and squarely, fit the washer over the pivot pin, chamfer facing outwards. It is most important to rivet the short pin, securely and neatly in position in the brake plate. Replace the second new threaded pivot pin and nut and expander cams. Reassemble the brake shoes and springs then locate the support plate over the brake cams. Secure the plate with set screws 26484 (1/4 in. UNF) and tab washers 060395 . Tighten the set screws then tap the tab washers into the position shown in the illustration. The brake is now ready to put back into service. March 1972 Norton Villier Canada Limited