The braking system is also part of the larger suspension system since it enables the control of the vehicle through the wheel control. An automotive suspension spring or the leaf spring is one of the suspension system components. Carriage or a leaf spring has been considered to be one of the simplest springs that are often used to offer suspension and linkages in vehicles. In addition, a leaf spring is known to be the ancient springing model that reminds one of the ancient medieval designs in the automobile industry. Most of these systems have got similar basic components and usually operate in a similar manner. Their differences are usually experienced in the arrangement method of their basic components. Generally, the spring is the core of nearly all suspension systems.

The component absorbs shock forces while maintaining correct riding height. If the spring is worn out or damaged, other suspension elements shift out of their proper positions and are subject to increased wear. The increased effect of shock impairs the vehicle’s handling. However, various types of springs are used in the suspension systems. These in clued the following coil, torsion bar, leaf inclusive of both mono and multi-leaf types, and finally air springs. Generally, automotive suspension springs are classified by the amount of deflection exhibited under a specific load. This is usually referred to as the spring rate. In relation to the physics law, a force (weight) applied to a spring causes it to compress in direct proportion to the force applied. Whenever that force is removed, the spring regains its original position if not overloaded (Erjavec and Knowles, 2003).

It is imperative to note that, a heavy vehicle requires stiffer springs than a lightweight car. Automotive springs usually take care of two fundamental vertical actions: jounce and rebound. Jounce occurs when a wheel of a vehicle hits a bump and moves up. When this action is experienced, the suspension system acts to pull in the top of the wheel, maintaining an equal distance between the two front wheels and preventing a sideways scrubbing action as the wheel moves up and down. Rebounce occurs when the wheel hits a dip or hole and moves downward. For this case, the suspension system acts to move the wheel in at both the top and bottom equally, while maintaining an equal distance between the wheels.