The following was published in CCJ's Air Brake Book, 11th edition, sponsored by Silverback HD. CCJ's Air Brake Book is a complementary industry resource courtesy of our partnership with Silverback HD, the Technology and Maintenance Council and Commercial Vehicle Safety Alliance. You can download the entire Air Brake Book here.
Electrification and hydrogen shoulder much of trucking’s potential to become a more environmentally friendly industry, but many fleets have already taken a green leap and may not have even noticed.
As of 2021, brake manufacturers were required to reduce the amount of copper used in their friction material to meet the copper-free brake pad agreement reached in 2015 between the U.S. Environmental Protection Agency, California and Washington State and industry representatives.
The agreement calls for reducing the amount of copper used in brake pads to less than 5% by weight (B-Level) on Jan. 1, 2021, and 0.5% (N-Level) by Jan. 1, 2025. Copper, the EPA said, is a primary pollutant of concern found in highway stormwater runoff, impacting aquatic life and water quality. The initiative also reduces mercury, lead, cadmium, asbestiform fibers and chromium-six salts in brake pads.
“Copper provides good thermal conductivity and heat dissipation to brake pads,” said Dhawal Dharaiya, engineering supervisor for Hendrickson Wheel End and Braking Systems. “In addition, copper plays an important role as a solid lubricant that helps generate a friction film during braking application to provide good wear characteristics. Materials that will eventually replace copper in brake pads must fulfill the complex properties that copper demonstrates in current formulations.”
ZF Commercial Vehicle Controls Systems Division Engineering Director Dirk Wohltmann added that since copper wears and oxidizes at high temperatures, it helps provide for better overall pad wear.
