Document rBJQ76ZyDVemq42gJ9nyQkoKr

SERVICE BULLETIN DECEMBER 8, 1978 T___ No. Q99 under brakes FOR BRANCHES. DISTRIBUTORS AND CUSTOMERS. CHASSIS AFFECTED ALLENT0WN2T HAYWARDL OAKVILLEvZl BRAKE DUST SHIELDS (All With FA(W)6l6c, 6l7c Front Axles) PURPOSE To provide part numbers of dust shields available for the cam brake assemblies used on these axles. RECOMMENDATION Dust shields should be installed as a product improvement on operations where the brakes are exposed to large quantities of dust, water and other contaminants. INFORMATION Dust shields were originally offered as optional equipment for the 16 1/2 by 5 cam brake assemblies 1QDA4239 and 1QDA4240 installed on these axles. In some cases it has been found desirable to retrofit shields on vehicles not originally equipped with them, due to adverse operating conditions. Dust shields can be installed without modification on current production vehicles. To install shields on non-current vehicles it is necessary to modify existing brake drums or replace them with current production drums. Current production drums have a re lief on inboard side that provides clearance for the shields. A similar relief can be added to non-current drums if desired. See illustration for dimensions. PLAINTIFF'S EXHIBIT MAC-88 raiN ltO IN USA IN THIS AREA TO PROVIOE CLEARANCE WITH SHIELD. 2. NONCURRENT PRODUCTION BRAKE ORUMS 00 NOT HAVE A RELIEF. Parts required per axle. Qty. New Part Description "T" i7Qj323aA-n-- * Brake Drum 2 17QJ3239A-P2 * Brake Drum 2 17QJ3240A 2 8235-A3236Z1794 12 4AX17 12 36AX3 * Brake Drum Dust Shield Service Assembly Screw, Dust Shield Mntg. Lockwasher, Dust Shield Mntg. Screw Replaces 17QJ323?)-]?1 17QJ3239-P2 17QJ3240 CIRCULATIC Service j Manager ; Shop Foreman Night Foreman Night Foreman Inspector Leadman Inspector Leadman Inspector Leadman Unit Over haul Room * Check chassis record to determine brake drum originally installed on vehicles. Chassis built after mid-1976 will be equipped with cur rent production brake drums. END Page 1 Q99 Service Operations, Allentown, Pa. U.S.A. Shop Office Mack