the way around. The problem with drum brakes was that they heated up easily and by heating up that would cause failure to the brakes, (Coates Del, Brake System 1). Drum brakes would mostly heat up when traveling down hill, as one would have to apply the brake often and there being no ventilation it was a accident waiting to happen. Most drum brakes where mechanically actuated (Coates, Brake systems 2). This means that the brakes where actuated by a cable and caused them to lock up very easily. The hydraulic brake was introduced in the 1950's (Coates Brakes Systems 3). This new braking system used fluid to apply pressure and greatly reduced lock up. Disc Brakes have become the premiere stopping system on cars today. Disc brakes do not trap water as drum brakes tend to do which causes them to slip and fail. Disc brakes also allow more surface area to accept pressure from the brake pads making stopping faster. In addition to disc brakes ABS (Anti-lock Braking System) was introduced on motor vehicles in the United States as a safety feature (Coates ABS Brake Systems). ABS brake system uses wheel speed sensors, a computer and a modulator unit to prevent loss of tire adhesion during braking. ABS is now available on over 90 percent of all new vehicles. The ABS brake system does not operate when you apply the brake unless one ore more tires starts to skid or lose traction. The technology of ABS now allows some systems to prevent wheel spin when speeding up or on slippery surfaces.The suspension system started out very basic. There where only two types; coil and leaf springs. The coils spring had a smoother ride but the leaf spring could hold more weight. Both where made out of metal and caused for rough rides by todays standards. This was a difficult desing and system to provide a smooth ride and good handling (Coates, Del Suspension 5). By 2000 the suspension system had changed to electronically controlled or air ride systems. Sock absorbers...
