The brake pedal uses leverage to transfer the effort from the driver’s foot to the master cylinder.
Different lever designs can alter the effort the driver needs to make. This is achieved by the utilization of mechanical advantage. This uses a second order level to gain its mechanical advantage or ratio.
The pedal is solidly mounted to the firewall, and works as a force-multiplying lever. If the power assist fails, the pedal's leverage is designed to allow the driver to still generate thousands of pounds of pressure at each wheel cylinder.
Brake pedals should be mounted securely and free from any excessive sideplay. As the brake pedal is attached to a master cylinder, manufactures endeavour to keep the master cylinder reservoir level higher than the horizontal plane of the brake stations to prevent/reduce the possibility of excessive drain back of braking fluid.
Brake pedals should be free to return when no pressure is being applied, allowing the master cylinder pushrod to return to its undepressed position. Binding in the pedal operation will lead to brake problems and could cause the brakes not to work efficiently under emergency stopping requirements.
Pedal height and angle is important for comfort and safety. Consideration must be given to the functionality of the driver are being able to lift their foot from the gas pedal to brake pad quickly. Correct spacing between gas, brake and clutch pedals is vital when the driver has to make a split decision to stop their vehicle.
Problems That Can Be Identified From the Pedals
Pedal pulsation, excessive pedal travel, a “soft” or “hard” pedal can be indicators of serious problems, including a leak in the hydraulic system, low fluid levels, or unevenly worn shoes or pads. Vehicles fitted with ABS brakes, it can be reassuring to feel that ABS-connected brake pedal pulsating beneath the foot during a full brake application, there is a reason to suspect a potential problem if the driver get the same pedal pulsation with a light to medium braking application.
Brake Light Switching
In vehicles fitted with ABS brakes, considerable pulsing can be felt through the pedal during a full brake application, however there is a reason to suspect a potential problem if the driver experiences the same pedal pulsation with a light to medium braking application.
Important
If there is any change in the "feel" of your brake pedal when applied in its normal mode, this could signal a potentially serious fault developing in the hydraulic system.
Source: CDX Global & Wikipedia - en.wikipedia.org
