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Old 10-29-2003, 08:32 AM
ktlimq ktlimq is offline
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Join Date: Aug 2003
Location: MA
Posts: 764
I would like to use MB pad instead of more expensive aftermarket pads.
The information I get is somewhat confusing. DaimlerChrysler and Akebono say seemingly opposite things.


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Talk at BIG 3 BRAKE SYMPOSIUM 2002
http://members.aol.com/carleyware/library/procut02.htm
by

Larry Carley

Once a year, brake engineers from the "Big 3" domestic auto manufacturers (General Motors, Ford & DaimlerChrysler) get together with tech types from various aftermarket service providers (Firestone, Goodyear, Big O Tire, Car-X, Merlin, Midas, Monro, Sears, Tuffy, Pep Boys, ProCare and others) to discuss brakes. The annual event, which is sponsored by Pro-Cut International, a manufacturer of on-car brake lathes, was held October 22, 2002 in Detroit, Michigan.

The purpose of this event is to allow aftermarket tech trainers to quiz OEM brake engineers about their recommend brake service procedures, new brake designs and any problems they are experiencing in their shops.

Keep in mind that the responses given by the OEM engineers reflect their opinions towards new car dealer warranty service procedures and fixes, not necessary repairs that work for the aftermarket.

Also keep in mind that the responses given by the individual engineers are not necessarily the "official" policy of the vehicle manufacturer they represent. In some cases, they expressed their own personal opinions rather than an "approved" service policy (no lawyers were present).

It's also interesting to note that the engineers from Ford, General Motors and DaimlerChrysler expressed opposite views on several important issues, including procedures for correcting brake pulsation problems caused by rotor lateral runout (GM approves the use of shims but Ford and Chrysler do not), the use of a lubricant or anti-corrosion treatment between the brake rotor and hub (Ford said yes, GM said never), and the use of brake pads that contain ceramic fibers (Ford and GM use them but Chrysler does not).





DAIMLERCHRYSLER PRESENTATION

DaimlerChrysler does NOT recommend installing aftermarket ceramic pads. They say these pads are highly abrasive to rotors and will accelerate wear and magnify roughness. If used on a typical SAE G3000 gray cast iron rotor, they will wear rapidly and create variations in thickness. This will cause a pad vibration (brake judder). Engineers call this "variable brake torque input." Jeep Grand Cherokee has had this kind of problem (see fix below).

Chrysler uses NAO and low-met pads on their vehicles. They want consistent performance. Ceramics are less predictable, so Chrysler is still evaluating ceramic materials.

ROTOR QUALITY?

Chrysler uses damped cast iron. Is better than standard gray iron. But is softer and wears more when aggressive aftermarket pads are installed. Rotor quality and noise characteristics vary a great deal with quality of iron alloy & cooling process. If make rotor alloy harder to extend rotor life, it reduces the rotor's ability to handle heat without heat cracking.








FORD PRESENTATION

WHAT'S NEW IN FRICTION MATERIALS?

Ford has used ceramic (potassium titanite) since 1993. Ceramic fibers improve durability.

"Ceramics" is hard to define. It's like baking cookies. A lot of ingredients go into a friction material and the manufacturer may choose to call it almost anything they want. Calling it a "ceramic" does not define how much ceramic is actually in the pads. It could only be a very small amount or a lot. Pad performance depends on all the ingredients that are in the pads. Same pads could be called NAO, low-metallic, semi-metallic, ceramic, carbon-metallic, you-name-it. It's all how the pad manufacturer wants to market their product. There are no standard industry definitions.

Semi-met pads are improving, and have less tendency to wear rotors and create runout and pedal pulsations.

Someone in audience said a certain brand of aftermarket ceramic pads are running hot, warping rotors. These are "ceramic" pads. They have a higher coefficient of friction which reduces stopping distance, but the wear problems they are creating may more than offset the other advantages these particular pads offer. Ford uses ceramic pads made by Akebono and have NOT experienced similar problems with the Akebono friction materials.


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Akebono web site

Rotor thickness variation and resulting pedal pulsation are also minimized through Akebono's ceramic technology. Akebono's patented friction material formulations include uniquely shaped ceramic particles that are less abrasive to the rotor surfaces. In addition, Akebono pads tend to contact the rotor in a more adhesive fashion to slow the wheel as compared to semi-metallic and other pads that are much more abrasive, attacking the rotor ad producing significantly more brake dusting. This unique approach reduces rotor wear by as much as 80 percent, thus increasing rotor life by as much as 400 percent versus semi-metallic and other pads.

Last edited by ktlimq; 10-29-2003 at 08:38 AM.
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