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D3EA Aftermarket Brake Lining Ratings

Fact: there are no federal performance standards for aftermarket brake linings. Most consumers don12t know that. Nor do most professional technicians. Most people assume replacement brake linings perform the same as or better than the original brake linings on a vehicle. In most cases they do. But without actually testing and rating the linings, there12s no guarantee.

The brakes on all new vehicles must comply with federal motor vehicle safety standard 105 (FMVSS 105) which specifies maximum stopping distances according to vehicle weight, loading, pedal effort (with and without power assistance) and brake condition (green & burnished linings). There are also requirements for fade resistance but none for wear or noise. In the year 2000, a new tougher standard (FMVSS 135) went into effect.

Two important points you need to know about FMVSS 105 and 135. One is that both standards apply to original equipment brake systems on new vehicles only. Neither standard applies to aftermarket replacement linings12which means aftermarket brake suppliers do not have to test their products for FMVSS compliance. The other point is that both rules are minimum performance standards. Many vehicles easily exceed the FMVSS standards while others barely pass. The same may be true for brake linings. Even so, some aftermarket linings may not make the grade and fall short of the FMVSS standards.

The only law that may be applicable is one that pertains to the installation of replacement parts. The federal Safety Act of 1966 (PL 95-599) says in Section 108, Paragraph 2(A):

"No manufacturer, distributor, dealer or motor vehicle repair business shall knowingly render inoperative, in whole or part, any device or element of design installed on or in a motor vehicle or item of motor vehicle equipment in compliance with an applicable FMVSS...

"For purposes of this paragraph, the term 12motor vehicle repair business12 means any person who holds himself out to the public as in the business of repairing motor vehicles or motor vehicle equipment for compensation."

One interpretation of this clause is that installers who replace brake linings with ones that take the vehicle out of compliance with the FMVSS standards are in violation of the Safety Act. The problem is, how do you know if the linings you12re installing meet FMVSS standards or not? Unless the linings are "certified" you don12t know.

Enter the "D3EA" test certification procedure. D3EA stands for "Dual Dynamometer Differential Effectiveness Analysis." It12s a relatively new test procedure that can predict with a high degree of accuracy the real world performance of any given friction material in a specific vehicle application. More importantly, it can certify with a high degree of confidence that a set of aftermarket replacement linings preserves complies with the FMVSS 105 and/or 135 requirements.

The D3EA test procedure is a voluntary certification program that is open to any brake supplier. Current users include Raybestos, NAPA and AC Delco. The testing, however, is only available through Greening Testing Laboratories Inc., in Detroit, Michigan.

The D3EA test uses a mockup of the front and rear brakes from an actual vehicle to simulate the interaction of the front and rear brakes12something which no single-ended dynamometer laboratory test procedure does. Both brakes (one front, one rear) are attached to a rotating shaft fitted with huge weights that simulate vehicle momentum. The brakes are then applied under very closely controlled conditions to determine the various aspects of brake performance. The results are then tabulated, plotted and compared against the performance "window" defined for the vehicle by the FMVSS standard. The test results show how closely the replacement linings match the minimum required OEM performance and where they fall relative to the FMVSS window.

Linings that pass the test can have the "D3EA Certified" seal placed on the product packaging. Passage does not, however, allow a brake supplier to claim D3EA certification for its full product line12only those linings that have passed the test procedure for a specific vehicle application.

Critics of the new D3EA procedure say it doesn12t cover enough applications (currently 31 different vehicle platforms) and is too expensive (about $5,000 per test). They also say brake testing on actual vehicles works just as well. But the proponents of D3EA testing say it eliminates many of the variables associated with road testing such as driver input, road surface, tire wear, suspension compliance, vehicle age, weather, etc. It can also establish an accurate baseline of OE brake performance, especially with respect to the FMVSS requirements.

What about edge codes? Comparing edge codes on brake linings doesn12t tell you much because edge codes only describe the hot and cold friction characteristics of the friction material and have little correlation to how the linings actually perform in any given brake application. There are too many variables involved. Edge codes are established by a simple "Chase" test that rubs a small square sample of friction material against a rotating drum to see how much drag it generates. It baselines the friction material but cannot predict how it will perform in a real brake system.


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