TMD Friction of North America has announced its new premium air disc brake pad friction material, Textar T3070. It has been specifically designed to work in conjunction with drum brakes to avoid potential compatibility issues between the two different brake types.
What's more, Textar T3070 has meet the FMVSS 121 dynamometer requirements of Technology and Maintenance Council's Recommended Practice 628, Aftermarket Brake Lining Qualification, as verified by SAE's Performance Review Institute.
As a result, TMD's friction material for 225 size calipers is the first and only air disc pad listed on TMC's list of approved replacement linings.
TMD is one of the world's leading manufacturers of brake friction materials to the automotive and commercial vehicle industry. It is also the largest supplier of air disc brake pads to the commercial vehicle sector and supplies advanced brake friction technologies to the motorsport market worldwide.
Friction requirements
"With the recent change in the stopping distance regulations and the growing number of disc brake equipped tractors, the braking friction requirements of new trucks are dramatically different to that of the typical truck on the road in the past," explains Jim Clark, TMD's director of engineering.
"Having a benchmark performance standard to understand the performance of a lining is key to making a good decision on lining and its performance in a newer vehicle."
In addition, TMD's premium drum brake lining, Textar T5000, has also passed RP 628 qualification testing for standard 16.5x7 drum brakes.
Together, these two products 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 recently released as standard or optional on all major truck manufacturers' vehicles, he notes.
Compatibility issues
Compatibility issues facing operators of vehicles with different brake designs on front and rear axles was 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 pre-mature wear," says Tom Green, general manager, TMD.
"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," he goes on.
"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. That is why TMD supports RP 628, and the inclusion of air disc aftermarket pads on this approval list."
"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," Clark explains. "Disc brakes generally have metallic type linings that continue to produce friction at high temperatures, while drum brakes typically use non-metallic linings that lose torque, or 'fade,' at high temperatures.
"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."
Material selection
Air disc brakes are excellent products, and are appearing in North America in growing numbers, observes Clark. However, "fleets need to understand that they have inherent compatibility issues with drum brakes.
"This, on top of a general lack of friction material regulations, makes the selection of aftermarket friction materials for air disc an even more critical decision for user fleets.
"TMD strongly supports TMC's RP 628, and is proud to be the first friction material company to have its air disc brake pad approved to this industry standard of performance."
