Document 2Ndj6Ky2yrgyBX2rvwjqoNNvL

FILE NAME Brakes BRK DATE 0000 DOC BRK188 DOCUMENT DESCRIPTION Published Report of Kourik P.E. - Friction Products - How They Work and Why They Contain Asbestos a ' FRICTION PRODUCTS THEY WORK AND WHY THEY CONTAINED ASBESTOS John W. Kourik P.E. CONTENTS 1 BACKGROUND AND FOUNDATION FOR EXPERT OPINIONS .1 1.1 EXPERIENCE WITH WAGNER ELECTRIC BRAKES . 1 1.2 INDUSTRY EXPERIENCE WITH BRAKES ..........--.-00e-- 1 .2 2 EXPERT OPINIONS .2 2.1 HOW DO BRAKES WORK 2.2 HOW AUTOMOBILE BRAKES BEGAN AND EVOLVED 3 2.3 BRAKES HAVE CERTAIN DESIGN STANDARDS AND 3 REQUIREMENTS 2.4 WHY THE BRAKE INDUSTRY USED ASBESTOS .5 2.5 WHY THE INDUSTRY HAD NO NEED TO SEARCH FOR ALTERNATIVES TO CHRYSOTILE ASBESTOS FOR SEVERAL YEARS AFTER WORLD WAR II .6 2.6 WHY THE INDUSTRY INITIALLY SEARCHED FOR ALTERNATIVES TO ASBESTOS ..7 2.6.1 NHTSA Safety Standards 8 2.6.2 CAFE Standards 8 SUBSTITUTES 2.7 INVESTIGATION INTO ASBESTOS FRICTION PRODUCTS IN It .8.8 2.8 DID THE FEDERAL GOVERNMENT EVER BAN ASBESTOS FOR HEALTH REASONS .... 8 Page 1 1 BACKGROUND AND FOUNDATION FOR EXPERT OPINIONS 1.1 EXPERIENCE WITH WAGNER ELECTRIC BRAKES My Curriculum Vitae is Exhibit 1 to this report and it identifies most of the experiences that I draw upon for the opinions expressed herein My experience in the design testing and production automotive brake assemblies spans 40 years of active employment In my capacity as first an engineer and then as the chief brake engineer for Wagner Electric | was familiar with the various types of brake systems in use for cars trucks and buses during the length of my career They basically break down to hydraulic systems or brake systems or a composite of air and hydraulic My work Included familiarity with the actual brake lining or friction material that those systems used I designed brakes made drawings for them supervised the manufacturing specifications and I witnessed the assembly and disassembly of brakes I am a professional engineer PE registered in the state of Missouri This required me to take certain examinations to qualify for the title of PE In my PE capacity I had occasion to conduct or supervise actual road tests or track examinations of brakes and brake systems with regard to temperatures and performance The friction products I have tested and specified were used on brake assemblies for passenger cars light trucks medium trucks busses coaches heavy trucks tractors trailers trailers and various industrial equipment My experience included brake assemblies and friction products used on overhead cranes specialized heavy industrial equipment and various types of construction equipment I have also done my own personal brake replacement with containing brakes Another significant part of my employment activity included the evaluation testing and specifying of friction products used for replacement purposes in the industry generally referred to as the aftermarket These replacement friction products included lining sets sets of block lining sets of lined brake shoes as well as pad sets for disc brakes 1.2 INDUSTRY EXPERIENCE WITH BRAKES When I was Wagner's Chief Brake Engineer my organization was a supplier of new brake assemblies and replacement friction and a purchaser of friction products This required continuous contact with many manufacturers of friction compounds This variety of sources and compounds involved a wide range of manufacturing processes to make the product in its several configurations and various means of attachment such as e Flexible strips riveted or bonded e Rigid strips riveted or bonded Page 2 e Segments riveted or bonded Blocks riveted or bolted e Disc pads riveted bonded or integrally molded I have been involved with setting brake industry standards through the Society of Automotive Engineering activities SAE SAE is an international organization that is charged with developing automotive standards recommended practices and other documents that relate to standardizing items of manufacture in both road motor vehicle equipment and aircraft During my career have participated equipment listed the items in my Curriculum Vitae on the committees or activities of the SAE I I according to the top rank and down to lower elevation of service For one year was the Chairman of the Motor Vehicle Council of the SAE which oversaw all of the standards recommended practices and the like that related to specifications These standards dealt with dimensional and performance automotive equipment We wrote standards for standards in the testing of brake linings or brake components test procedures that were incorporated into the federal motor vehicle safety standards I have published articles relating to the brake manufacturing industry In 1951,1 1951, a related to the design of the industrial brake system overhead crane published paper work on measuring the stopping distance to meet brake system followed by some In October 1964 I published an SAE paper safety standards for rubber mill operation brakes and that dealt with theoretical comparison of the two major brake types cam wedge brakes that are still used on vehicles today I have also had occasion to testify before governmental agencies regarding brakes and highway safety in connection with brakes For example I participated in house committee hearings related to brake regulations I participated in Senate hearings related to antilock or control regulations for commercial vehicles and I have participated in dozens of public meetings related to the regulation of brake systems brake components and vehicle performance since the Department of Transportation was organized in 1965 2 EXPERT OPINIONS 2.1 HOW BRAKES WORK The of the brake system is to stop and control the vehicle The brake performs purpose vehicle that is moving along at that function by taking the kinetic energy of the Page 3 its and converting that energy into heat at the friction interface with the drum or speed transformers During a brake disc Brakes can be viewed quite simply as energy rotor the friction material makes contact with the rotating drum or disc application the relative motion between the two bodies Using the creating a friction force resisting into the drum where it can be dissipated in the air the brake then forces the heat 20 pounds of driver pedal lining As an energy conversion device the brake miraculously uses traffic force to stop a pound vehicle at a comfortable change in speed in city 2.2 HOW AUTOMOBILE BRAKES BEGAN AND EVOLVED apparent As the first motor vehicles increased in speed and weight it became that wheel external band brakes on the rear axle did not have the ability to dissipate The next step was to add external band brakes to the the heat being generated to convert from external mechanical A steered wheel on the front axle third step was enclosed within a brake brakes to internal mechanically applied shoe brakes banddrum Early in the 1920's internally actuated hydraulic drum brake became the newest entry into this ongoing product evolution Since that time hydraulic actuated brakes have continued to evolve in and safety Long brake and brake system development however sophistication evolved Brake development has also been has never been revolutionary It has is a careful tedious and unrelenting privately funded activrietlyiaTblheesevtoluteionparyrperfoicneemsesnt from any level of safe challenge to parnodvidduerability to another safe level of performance and durability performance specific expertise is not practical to define the stages of this engineering evolution in blocks of time The majority of these improvements took polfavceehiincloevemralnaupfpaicntgursetrespseach because of the many industry entities involved The host relied on a multiple base of suppliers and their sources of materials and 2.3 BRAKES HAVE CERTAIN DESIGN STANDARDS AND REQUIREMENTS hostile The friction material inside of a brake must operate in a rather in excess of 400 750 are not unusual and environment Lining temperatures exceed 850 1560"F1560"FThe nature of the temperatures at the contact interface can mud salt water etc. complicates the road operating environment dust balance of characteristics optimized problem The friction material must possess an miles of vehicle and maintain those characteristics throughout 20,000 to 40,000 operation Page4 avoided Friction level must be adequate and stable over a wideorfatnhgeecoofndoipteiroantiinnggand speeds application pressures and temperatutrheesrreegcarodvleessry characteristics i.e. the age of the material Oflepvaerltidceutlearrioirnatteiroenstwahreen subjected to extreme elevated level on cooling the ability to resist friction friction temperatures the fade and then to return to the fade for life but it must The friction material must have good wear properties long recovery on the mating disc or drum Excessive also not cause excessive wear or groocvhiantgter vibration pulsation must be compressibility noise and rmouusgthbneesmsinimized Finally the friction material must be and sensitivity to moisture capable of being manufactured with consistency one characteristic often results in the In general attempting to improve upon of friction materials is therefore deterioration of other characteristics The development combination of interdependent a complex interactive process seeking an optimized characteristics brake designs provides another level of complexity in The existence of numerous require a wide range of properties designing friction materials Linings for drum bUr.Sa.kedsesign at one time required two The servo drum brake the most popular and secondary each of which needs different types of linings designated primary friction level and friction stability The different properties of strength wear resistance vehicles requires a friction drum brake used on many compact and the secondary servo material which incorporates the best characteristics of the primary and static friction formulation with emphasis on temperature properties Into a single The large hydraulic and operated drum brakes utilized on medium and capability the maximum properties of the smaller vehicle linings heavy trucks require in general The arcuate form of drum brake but at significantly higher operating temperatures because of processing linings places additional restrictions on the formulation requirements different set of operating conditions for the friction a Disc brakes demand totally than drum materials Disc brakes generally operate at signiftihceanrtelayrhdigrhuemr tbermapkeersaotnurtehse same brakes and the front disc brakes run hotter than for these material for disc brakes must be specifically designed vehicle The friction coefficient of friction and better wear a and must possess higher formulations must also higher temperatures material characteristics across the temperature range be tailored to the specific needs of the particular vehicle applications Numerous such as vehicle weight front brake balance actuating system pdaersaimgentearnsd duty cycle affect the capability of a particular friction formulation to perform satisfactorily performance standards emanating from The existence of numerous complex associations manufacturers and government agencies provides an consumers must meet Significant differences additional set of parameters that friction materials Page 5 manufacturing manufacturing Government materials used as original equipment in new vehicles and can exist between friction in the aftermarket Each vehicle friction materials available as replacement parts standards to ensure has a unique extensive set of test and acceptance used manufacturer of its products and the components the safety durability and performance exist at the federal state and local levels therein requirements by the Department of Transportation Federal requirements include tthhoesOeccpurpoamtuilognaatledSafety and Health Administration Protection Agency DOT vehicle performance and the Environmental work practices OSHA practices and raw materials EPA 2.4 WHY THE BRAKE INDUSTRY USED ASBESTOS woven material composed of cotton and In the 1890's the first brake friction was uniform and stable friction horsehair It had to be impregntahteedtuwrintohfbtihteumciennttourpyrotvhiedeincreasing speeds of the brake friction during brake applications Byand the increasing weight was creating new mode of transportation Fahrenheit This temperature charred the cotton and temperatures of 300 degrees destroyed it fibers were already being converted into thread and became Chrysotile asbestos that needed heat resistance the obvious material of choice for a woven application in various widths and varying above 300 degrees It continued to be produced were developed for pressure thickness until the dry mix and wet mix compounds curing to provide a more uniform friction produce asbestos met the rigorous design specifications for Until the early 1980's only stated automotive friction materials must brake industry As previously Friction materials must maintain the automotive operate reliably in an extremely hostile environment miles of vehicle operation and balanced characteristics throughout 20,000 to 40,000 brake application pressures must remain stable over a wide range of operating speeds of the material and temperatures regardless of the conditioning or age chosen for use in automotive friction Processed chrysotile asbestos fiber was meets these needs The combination of characteristics stable friction level materials because its unique of friction provides a high material possesses a high coefficient It has excellent thermal under a wide range of vehicle and envifroornmbeonthtarlescionndbiitnideornssystems and friction stability has good surface absorapntidvdituyrability has high strength and reinforcing modifiers possesses flexibility characteristics The high level of characteristics and has very low noise generating the drum where it could be forced the heat into rubber seals resistance to thermal conductivity the heat of braking from destroying dissipated was essential to prevent of the brake fluid in the wheel cylinder and to prevent boiling dynamometer Page 6 in the evaluation of brake friction included measurement My professional work installed in the brake lining on vehicles and on of lining temperatures by thermocouples in the effects of temperature on installations Additional experience the testing of friction products from data developed during with the SAE Brake brake frictionmwaacshionbetaiSnuecdh tests were conducted in accordance made it on Chase J661 Collectively these tests Lining Quality Control Test Procedure of containing brakes for control ~ apparent that the dust generated during use Examination of the wear products of the vehicle is not one single type of wear product the metal worn off of the it to be a combination of many constituents including under the high heat shows that are cooked out of the lining ~ lining interface and the resins of braking NO NEED TO SEARCH FOR ALTERNATIVES TO ! 2.5 WHY THE INDUSTRY HAD FOR SEVERRAL YEARS AFTER CHRYSOTILE ASBESTOS FRICTION WORLD WAR II the technology that had been After World War II the industry ebnedguarnaanpcpelyainndg performance on improved roads increase the created during thetowllarroaHdisghaenrdstpheeeIdnterstate Highway System began to i e.g. tumpikes or heat dissipation demand on the brake systems successfully developing improved resins for this - The industry responded by demand The resin improvements kept pace with the higher operating temperature the increased vehicle weights that were occurring This performance demands and established brake performance requirements enabled the brake . - ability to meet the feature of chrysotile asbestos for drum brakes engineers to retain the good insulating personallyHowever there were some specialapploifcoatthieornsmfaonrufpaacstsuernignegrtceacrhsnithqautes challenged the friction industry to attempotftthheeussheortcomings of the ceramic friction 7 and other material recipes am aware that sintered metallic friction offerings I am also aware of the several problems the broad spectrum of test procedures submissions demonstrated when subjected to The brake test facilities at ~ needed to assure safe performance to the general public of test vehicles I have dynamometers and a fleet drum brakes I Wagner Electric included inertia with sintered metallic friction on vehicles equipped operated of the dangerous problems reported by others have personally encountered some Page7 have reviewed the complete 1959 Society of Automotive Engineers SAE paper entitled What's New in Brake Lining My evaluation included data provided in the 13 illustrations that the author considered important to his topic The 1959 sintered metallic friction despite surviving one severe demonstration on the Pike's Peak Highway failed to meet all of the following basic criteria for safe vehicle operation that are a part of the text of the paper 1. Low wear rate 2.2. Minimum friction variation 3.3. Resistance to high temperature and fading 4.4. Compatibility of lining surfacewith drum surface 5.5. Standard brakes or power brakes must engage smoothly with low pedal effort and operate effectively 6. Lining and drum engagement sounds must stay below audible level 7. Low acquisition cost for friction material 8. Low warranty cost and low replacement cost There is a 1975 SAE paper entitled Development of Police Car Brake Standards that details the frustrating problems associated with the ongoing attempts to develop a satisfactory sintered metallic friction product to replace chrysotile asbestos friction The report identifies many faults that were never corrected - hence the sintered metallic friction programs drifted into obsolescence 2.6 WHY THE INDUSTRY INITIALLY SEARCHED FOR ALTERNATIVES TO ASBESTOS Use of chrysotile fibers in brake friction was phased out because of new brake performance requirements that made asbestos obsolete New friction materials were developed using mineral MMMF to meet the engineering demands that resulted from two Federal actions 1 Federal Motor Vehicle Safety Standards promulgated by the DOT's National Highway Traffic Safety Administration NHTSA and 2 EPA regulations to implement and enforce the Corporate Average Fuel Economy CAFE requirements for new motor vehicles Page 8 2.6.1 NHTSA Safety Standards In January of 1965 the Federal General Services Administration GSA required dual split operation on all vehicles they purchased The industry extended that design feature on all passenger cars by model year 1967. Between 1965 and 1976 Federal Motor Vehicle Safety Standard 571.105 FMVSS 571.105 evolved into a very complex required performance document Some of the revisions introduced included but were not limited to . Stopping distance requirements for the full brake system . Stopping distance requirements for both of the partial systems in the event of a single hydraulic failure Grade holding capability on a specific grade in both directions uphill and downhill All vehicles had to be certified to comply with FMVSS 571.105 To meet all of those requirements the vehicle manufacturers had to radically change the braking distribution to 90 front axle and 10 rear axle A new friction material had to be developed or found because asbestos did not have the ability to dissipate 90 of the heat of braking without destructing 2.6.2 CAFE Standards The introduction of friction materials that did not include chrysotile asbestos started after the CAFE regulations were issued circa 1975. Weight reduction was one key change needed to comply with the CAF^ requirements Some brake components were reduced in durability Increased friction operating temperatures resulted The introduction of a new family of fibers followed They were referred to as the MMMF and could function at temperatures that destroyed chrysotile fibers Some of the fibrous materials were metallic in composition 2.7 INVESTIGATION INTO ASBESTOS SUBSTITUTES IN FRICTION PRODUCTS In 1987 due to reported health problems associated with the use of asbestos the EPA's Office of Toxic Substances proposed a regulation to ban the use of asbestos over a year phase period Since asbestos was a critical constituent in some vehicle friction products the EPA was interested in determining whether the proposed ban could have adverse effects on vehicle braking safety Page 9 In order to assess the potential effects of the proposed ban on vehicle brake system operation and vehicle safety the EPA contracted with an entity to make an evaluation The EPA chose the American Society of Mechanical Engineers ASME A panel of individuals knowledgeable in various aspects of vehicle brakes was selected The panel addressed technological issues associated with the removal of asbestos from friction materials specifically ( Identification of substitute brakes and systems 2 | Compatibility of the ban with motor vehicle safety standards 3 Problems associated with replacing asbestos friction materials in aftermarket vehicles and 4 Pace of research and commercialization and effects on phase The bottom line conclusion from this analysis was that attempting to immediately substitute asbestos products created greater consumer safety risks than the continued use of asbestos There were several bases for that conclusion Vehicle controllability during braking is affected by both driver and brake system performance Generally vehicle front braking ratios are adjusted on a model basis to provide optimal braking Too much braking on an axle results in premature wheel lockup and this can lead to loss of steering control front lock or spin rear lockup While the effectiveness of disc brakes is directly proportional to disc friction levels the effectiveness of drum brakes can be greatly affected by changes in lining friction Friction materials that exhibit reduced effectiveness also can result in brakes having insufficient torque needed to stop the vehicle Different drum brake designs exhibit dramatic differences in effectiveness The majority of the automobiles sold in the United States at the time were fitted with front disc brakes and rear drum brakes Because of differences between qualification standards cost driver preference and driving conditions in the United States and Europe American and Japanese automakers were utilizing rear drum brakes Suitable asbestos materials were not available for all of these applications and industry substitution of asbestos materials in all existing brake designs would require considerable development The substitution of unqualified asbestos friction materials in the after market however posed the largest potential safety issue Because vehicle controllability during braking is strongly affected by friction material performance unqualified substitution of friction materials in either vehicle disc pads or drum linings may have had an adverse effect on vehicle brake balance and controllability A large Page10 number of older vehicles in the United States have brake systems designed for asbestos friction products The use of unproven materials in place of proven asbestos materials in existing systems could have resulted in a loss of vehicle controllability during braking Moreover in 1985 there were no required performance tests for aftermarket brake friction materials and most of the aftermarket asbestos material suppliers lacked the facilities to evaluate their materials under dynamometer and vehicle braking test conditions It was determined that mandating aftermarket nonasbestos friction materials for vehicles that were originally equipped with asbestosbased linings could lead to a potentially serious consumer safety risk In sum while there were alternatives to asbestos fibers being examined the composites were structurally inadequate producing tear and poor wear resistance in addition to roughness All formulations were considered failures This led to the conclusion that simple direct substitution of alternative fiber systems was not practical In fact the asbestos substitute drum brake materials originally contemplated lacked the insulating capability of asbestos and could not be safely used for replacement friction RECORDS FROM 300 Lawyers Building / Pittsburgh Pennsylvania 15219 / 412 642 +420 Fax Number 412 642-9088 ORIGINALS a JOHN W.KOURIK P.E. 1135 OLIVAIRE LANE ST LOUIS MO 63132 314-994-7657 Curriculum Vitae Graduate BSME 1948 Washington University in St. Louis Missouri Registered Professional Engineer 6533 State of Missouri Member Society of Automotive Engineers SAE Engineer's Club of St. Louis Missouri Member _National Society of Professional Engineers President's Club Wagner Electric Corporation Detailed Service to Industry Groups Chairman Motor Vehicle Council of the SAE - 1978 Wheel Slip Brake Control Systems Subcommittee of the SAE Brake Committee - 1973 Publication Advisory Committee of the SAE - 1972 Brake Rating Subcommittee of the SAE Brake Committee - 1964 Vice Chairman Motor Vehicle Council of the SAE - 1977 SAE Brake Committee - 1974 Member Parking Brake Subcommittee of the SAE Brake Committee Nomenclature Subcommittee of the SAE Brake Committee Dynamometer Subcommittee of the SAE Brake Committee Road Test Procedure Subcommittee of the SAE Brake Committee and Vice Chairman of its Passenger Car Task Force Liaison Rep SAE Brake Committee to the SAE Hydraulic Brake Systems Actuating Committee Assoc Member Association of Iron and Steel Engineers Consultant To the Joint TTMA Brake Committee Automobile Manufacturers Association - Truck Trailer Manufacturers Association and Member of Its Brake Rating Horsepower Task Force Member Braking Equipment Subcommittee Western Highway Institute Brake Task Force of the Truck Trailer Manufacturers Assn Advisory Committee Engineering Department Florissant Valley Community College St. Louis Missouri Employment Record - Wagner Electric Product Engineering Department Student Engineer June 1948 Laboratory Project Engineer October 1948 Junior Mechanical Engineer November 1949 Project Engineer Industrial Products October 1950 Supervisor Industrial Products Section April 1956 Supervisor Hydraulic Brake Products Section November 1961 Chief Engineer Brake Products April 1966 Director Parts Management Marketing September 1981 Director Brake Engineering & Aftermarket Services September 1983 Retirement date - June 30 1988 1/99