Bob Weber is president of Virginia-based Write Stuff. He is an award-winning freelance automotive and technical writer and photographer with over two decades of journalism experience. He is an ASE-certified Master Automobile Technician, and has worked on automobiles, trucks and small engines. He is a member of the Society of Automotive Engineers (SAE) and numerous other automotive trade associations. He has worked as an auto service technician, a shop manager and a regional manager for an automotive service franchise operation.
Brakes have been around for as long as the wheel. The original friction material was probably Fred Flintstone’s feet. Romans saved their sandals by using wooden blocks pressed against the wheels of their chariots.
The evolution of vehicle brakes has been surprisingly slow. In two millennia, brakes changed very little. In the early days of America, wagons and stagecoaches still used the wooden block and lever brake system.
However slowly, brake technology may never stop evolving.
One of the greatest issues precipitating change is legislation calling for an end to copper in brake pads.
In the 1990s, towns south of San Francisco were having trouble meeting Clean Water Act requirements to reduce copper in urban run-off flowing into San Francisco Bay. Preliminary studies indicated that brake pads were a significant source of that copper. Tiny amounts of copper fall onto the streets and parking lots every time drivers step on their brakes. Then, when it rains, that copper is washed into nearby streams and rivers. Although copper is essential for the health of both plants and animals, excessive amounts are harmful.
The Brake Pad Partnership, a cooperative effort among representatives of the auto industry, brake pad manufacturers, environmental groups, storm water agencies and coastal cities, discovered that the use of brake friction material accounts for anywhere from 35% to 60% of copper in California’s urban watershed run-off. The group’s members determined a course of action that would address the issue. The partnership decided that the most effective and fair thing to do would be to pursue legislation mandating the phased reduction of copper used in brakes.
Copper has long been used as a friction modifier in ceramic formulations. In some brake pads, copper was as much as 20% of material content by weight.ccording to the Copper Development Association, a U.S.-based, not-for-profit association of the global copper industry, copper makes for a smooth braking, transfers heat efficiently and improves stopping in cold weather. Copper also helps prevent squealing and shuddering caused by pad vibration.
As a result of legislation enacted in 2010 in California (SB346) and Washington (SB6557), copper must be reduced to one-half of one percent or completely phased out by 2021 in Washington and 2025 in California.
The Copper Development Association supports the conclusion of the Brake Pad Partnership and its plan to phase out copper from brake pads over a 15-year period.
The evolution of copper-free brake pads has already begun and it will soon affect the entire automotive repair market.
“The automotive industry is shifting to low-copper or no-copper content in braking products,” stated Dr. Mark Phipps, director, R&D and engineering for Bosch Braking Components, North America. “Bosch has been using its patented copper-free ceramic material in the premium grade QuietCast line of braking products since last year,” he added.
OE vehicle manufacturers reportedly began using low- and zero-copper formulations in millions of vehicles in the 2014 model year. As a result, low-copper technology will be coming to all markets, not just Washington and California, on many popular models.
Gearing up for the challenge
Brake component suppliers are gearing up for the challenge.
Wagner Brake engineers, for example, developed a unique process called tribological “fingerprinting” that enabled them to isolate and map the behavior of copper within the friction material over a full range of operating conditions. Once they fully understood how copper reacts during brake operation, they were able to substitute and compare the behavior of some 1,500 alternatives. Each Wagner OE21 formulation represents a unique matrix of several of these new materials as needed to meet the braking requirements of the corresponding application.
The new, 2021-compliant Wagner ThermoQuiet CeramicNXT pads offer 15% more stopping power, up to 40% greater fade resistance and are 35% quieter than previous ThermoQuiet ceramic formulations, according to the company.
Introduced last year, Raybestos Element3 brake pads are reportedly the world’s first hybrid brake pad to deliver the best attributes of both ceramic and semi-metallic. The pads are formulated for long life and reduced dust.
Element3 is a result of the engineering expertise and extensive testing done at the Brake Parts Inc. (BPI) research and development center. Raybestos hybrid formulations are not only environmentally correct and suited for the applications, but are also solving issues such as rust jacking. This is a common problem that customers experience when ceramic pads are installed on the vehicle when it might not be the best choice for that specific application. The pads meet the SAE J2521 standard for noise.
Check for the LeafMarks
How can you tell if a set of brake pads are 2021-compliant?
The automotive aftermarket suppliers and brake manufacturer have developed a series of trademarks called “LeafMarks” to be used on product packaging and brake pads.
“The Automotive Aftermarket Suppliers Association (AASA) and Brake Manufacturers Council (BMC) are pleased to be associated with NSF International and its nearly 70-year history of certification coupled with its extensive automotive industry experience,” said Bill Long, AASA executive vice president and executive director of the BMC.
NSF International has been granted the right to authorize the use of the BMC’s LeafMark to manufacturers that are in compliance by way of stringent testing standards.
“The BMC is committed to reducing the role of copper and constituents contained in brake friction material. Over the last several years, the Council appointed a committee which developed certification guidelines, product and packaging marking and worked with the Society of Automobile Engineers (SAE) to create material testing standards,” said Brake Manufacturers Council Chairman Bob Wilkes.
To help technicians know which of the three levels of compliance a brake pad has reached, the LeafMarks will appear on the packaging as well as the brakes themselves. There are three different LeafMarks — one for each level.
- Level “A” regulates cadmium, chromium, lead, mercury and asbestos.
- Level “B” is the same as A but copper must be less than 5% by weight.
- Level “N” is the same as B but copper must be less than 0.5% by weight.
It will become increasingly important for professional auto technicians to use the correct brake pads for the application.
“Each vehicle is designed to meet specific performance targets and designs are constantly changing,” said Bosch’s Phipps. “If a ceramic material is used on a vehicle that is designed to operate with a semi-metallic, the most common failure is rapid wear with high levels of wheel dust. Likewise, if a ceramic material is replaced with a semi-metallic, the likely failure will be due to brake noise and excessive rotor wear. Therefore the best practice is to replace like with like.” ●