TMD Friction of North America’s premium air disc brake pad friction material, Textar T3070, has met the FMVSS 121 dynamometer requirements of the Technology & Maintenance Council’s (TMC) Recommended Practice #628 – “Aftermarket Brake Lining Qualification,” as verified by SAE International’s Performance Review Institute. The announcement was made at the American Trucking Association’s (ATA) recent TMC annual meeting, where TMD claimed that its friction material for 225 size calipers is the first and only air disc pad listed on TMC’s list of approved replacement linings.
TMD Friction’s premium drum brake lining, Textar T5000, also passed RP 628 qualification testing for standard 16.5- x 7-in drum brakes. Together, these two products are said to offer the first TMC-approved replacement option for newer tractor designs with air disc brakes on steer axles and drum brakes on drive axles, a configuration that has recently been released as standard or optional on all major truck manufacturers’ vehicles, according to TMD Friction.
Compatibility issues facing operators of vehicles with different brake designs on front and rear axles were a major reason TMD developed and certified to aftermarket standards a disc brake pad formulated to replicate the performance of drum lining material.
“The driving force behind our pursuit of TMC’s approval is that we believe the growing number of air disc brakes in the North American market could trigger a rash of disc/drum brake compatibility issues, including rotor cracking and premature wear,” explained Tom Green, TMD’s General Manager. “Also of concern is the entrance of potentially inferior aftermarket disc brake pads. The key to TMD’s T3070 air disc pad formulation is that its high energy performance ‘matches’ the high energy performance of typical North American drum brake linings, assuring compatibility between two types of brakes that can cause problems for truck operators.
“Unfortunately, North America has a higher probability of these issues than Europe, where air disc is the dominant brake, due to the lack of aftermarket lining regulations here,” Green continued. “That is why TMD supports RP 628 and the inclusion of air disc aftermarket pads on this approval list.”
Jim Clark, Director of Engineering for TMD, notes that disc and drum brakes differ in both the way they mechanically react to higher temperatures and the type of linings that are typically used on them. “Disc brakes generally have metallic-type linings that continue to produce friction at high temperatures, while drum brakes typically use nonmetallic linings that lose torque, or ‘fade,’ at high temperatures,” he explained. “The T3070 pad chemistry is formulated to give significantly longer life, reduced rotor scoring and cracking, and improved compatibility to North American drum brakes, when compared to other available disc brake pads.”
The formulation, which is available through Textar-authorized distributors, was under development and testing for more than two years. T3070 is specifically designed for class 8 on-highway tractor and trailer applications with disc brakes being used in conjunction with drum brakes.
Textar also offers specific air disc brake pad formulations for other applications including all disc brake-equipped class 8 tractors, all disc brake trailers, city transit buses, and refuse and other severe-duty trucks.