|MARK’S CORNER – AUTO REPAIR HELP|
|Brake System Overview
by Mark Davidson
Early automobile brake systems consisted of cable operated brake lining, usually mounted on one axle. The system provided extremely poor stopping power and did not always apply brake pressure evenly to the wheels. This could cause one wheel to lock up and make the vehicle difficult to control during stops. Front brakes were rarely equipped on early vehicles. The need to have the front wheels move from side to side for steering made installation of a cable operated brake system an engineering nightmare. The invention of hydraulic brake systems provided safe, high powered and even braking for automobiles and light trucks. Hydraulic brake systems have been in use for several decades. While the last thirty-five years has seen a number of changes made to the brake system, the basic principle of operation has remained the same since the use of hydraulic brakes began. There are some auto repair garages which specialize in automotive braking andsuspension, but any auto repair shop should be able to inspect and make the necessary brake repairs.
What makes hydraulic brakes possible is the fact that a liquid cannot be compressed. This is the primary operating principle of all hydraulic systems. Hydraulic theory states that when pressure is placed on a liquid in an enclosed system, that liquid exerts the same pressure, equally in all directions inside that container. This is what allows a master cylinder to apply even brake pressure to all four wheels of a vehicle. If a master cylinder generates 1000 psi of pressure to the left front wheel, it also is transmitting 1000 psi to every other component in the brake system.
While hydraulics provide the operating force for the brake system, it is friction that causes a vehicle to stop. The energy that is created by a moving vehicle is converted to heat during stopping, by the friction of the brake linings against the brake rotor or drum surface. The heat generated is then dissipated through the rotors or drums to the outside air. It is the ability of these brake components to dissipate heat, that makes safe stopping possible. Heat buildup in the brake linings and drums or rotors during repeated heavy braking, can cause loss of braking power or brake fade. The ability to rapidly disperse heat is one of the characteristics that make disc brake systems so desirable. No automotive system is as important as your brakes. Therefore, you should inspect or have an auto repair mechanic inspect your braking system regularly. Make sure the repair shop flushes your brake fluid at least every 24,000 miles.
(Mark gave up on sports when the Browns left Cleveland and now spends his Sundays working under a shade tree in the back yard tuning his son’s soap box derby car.)