Document onz98roDLkYQ8bdLOn0z4XO3

>], .Ju I Vsc. 197/ A.. A/wi-tASr^ R-120 R FRICTION MATERIALS AND SYSTEMS 1. New Materials Laboratory testing of both vet and dry-mix disc brake formulations Indicated that dry-mix formulations would be the most suitable for vehicle usage. Based on this result, dry-mix formulations were selected for dynamcoeter testing. A formulation containing Jf> lithium fluoride showed excellent performance for high energy stops on the dynamometer test; however, recently processed disc brake pads of the same formulation shoved high wear of the cast iron rotors and about tvice the lining wear of the earlier samples. It was subsequently discovered that the more recent lining samples were made from a newer supply of Johns-Manville 5K30 grade asbestos. This asbestos was found to contain about 6$ magnetite In large pencils, enough In quantity and form to account for the observed hlgi case iron wear rates. Contact with the asbestos supplier revealed that most brake lining vendors are now using the more highly processed 5K04 grade asbestos in their disc brake formulations because 5K30 asbestos which Is low in magnetite content is no longer available. The added processing to produce the 5K0k grade breaks apart the asbestos crudes and permits removal of the large cagnetlte pencils. Additional samples of our experimental linings were made using new 5K0h grade asbestos. This substitution eliminated the cast iron wear problem but dynamometer tests showed unsatisfactory fade recovery characteristics and lining vear rates above those expected from the earlier teats of this formulation with the old 5K30 grade asbestos. It la believed that the lees crudy (fine fiber) 5KDU grade asbestos does not provide enough lining permeability to permit rapid recovery from fade testing and It does not provide enough coulomb damping to !:iQ ff PLAINTIFFS | EXHIBIT S WV-06345 PLAINTIFF'S EXHIBIT i3LBL0 SCF-ALLF-03440