Brake S-Cam Tube Bracket Failure

BACKGROUND In a letter dated January 15, 2012, Navistar, Inc. (Navistar) notified the NHTSA that it had decided a defect exists in certain Model Year 2012 and 2013 International brand ProStar and TranStar commercial trucks, manufactured from August 1, 2011 through June 12, 2012, and equipped with brake S-Cam tube bracket assemblies. The brake S-Cam tube bracket assembly on the steering axle may exhibit fractures between the wing bracket and the tube steel when mounted. According to Navistars filing, fractures between the wing bracket and the tube steel may result in an inoperative brake on the affected wheel end resulting in an unexpected pull condition during braking application or an unexpected increase in stopping distance. Either result may increase the risk of a vehicle crash. NHTSA assigned recall number 12V-546 to this matter. On May 28, 2013, the Recall Management Division (RMD) opened this Equipment Query Investigation in order to write to the company that supplied Navistar with these brake S-cam tube bracket assemblies, to notify the supplier of this defect, and to ensure thorough safety recalls are conducted where appropriate. An Information Request (IR) letter was sent to Meritor, Inc. (Meritor) on May 31, 2013 requesting: a list of original equipment vehicle manufacturers and after-market customers that purchased the affected brakes; the name, address and phone number of a contact for each customer; the quantity sold; the dates shipped; and, a defect report. MERITOR RESPONSE In a letter dated June 13, 2013, Meritor responded to the IR letter and reported that based on its review of the data and information on the brake S-cam tube bracket assemblies, it did not believe these brake assemblies contain a safety related defect. Meritor investigated returned components and determined that fractures in the brake S-Cam tube bracket assemblies resulted from vehicle front-end system vibration; and, there were no defects in the design, material or manufacture of t