Modern car manufacturers continually strive to develop innovative concepts that enhance the driving experience, making it safer and more comfortable. Among these innovations is the power brake system, now a standard feature in modern vehicles. Unlike the traditional drum brake system, which requires considerable effort to stop the car, the power brake system amplifies the force applied to the brake pedal. This exponentially reduces the physical effort required, resulting in smoother and more responsive braking.
Although power brakes are not technically essential for driving, they improve braking performances, particularly in larger vehicles or during emergency stops.
This blog will explore how power brake works and the different types of power brake systems available.
How do Power Breaks Work in Cars?
The car power brake system is designed to provide more efficient and responsive braking of the car. Its working can be summarised as follows:
Force applied by Brake Pedal
When the driver presses the brake pedal, a small amount of force is exerted on the braking system. This force is generally insufficient to stop a vehicle moving at high speed. The power brake system amplifies this force using various mechanisms, making it adequate to halt the vehicle.
Vacuum Booster Mechanism
Most car power brake systems use vacuum boosters, also known as brake boosters, to amplify the force. In traditional systems, the vacuum is generated by the engine’s intake manifold, while modern cars use a vacuum pump. When the brake pedal is pressed, A valve allows air into a chamber, pushing a diaphragm against the vacuum. As a result, the brake pedal applies more force.
Hydraulic System
In hydraulic systems, pressing the brake pedal generates hydraulic pressure. This pressure forces the brake pads or shoes against the rotors or drums, stopping the car effectively using the hydraulic pressure.
Electronic Assist
Many modern vehicles are equipped with Electronic Brake Assist (EBA). EBA detects an emergency braking situation and provides additional braking power, ensuring quicker and safer stops.
What are the Types of Power Breaks in Cars
Car power brake systems vary based on their functionality and the method used to amplify braking power. Below are the main types:
1. Vacuum Assisted Boosters
This is the most common type of power brake system. It utilizes a vacuum, either generated by the engine or a pump, to amplify the braking power.
Advantages: Simple design, reliable, cost-effective.
Limitations: Ineffective if the vacuum system fails, such as during engine stalling or a faulty vacuum pump.
2. Air Assisted Boosters
Commonly found in big commercial vehicles, these brake boosters use compressed air to amplify the braking force.
Advantages: Highly effective for big vehicles and equipped with spring brakes in case of failure.
Limitations: Not suitable for small cars because of size and complexity.
3. Hydraulic Assisted Booster
This system uses a hydraulic pump to generate hydraulic pressure which is then used to amplify the braking force.
Advantages: Highly reliable and effective for large vehicles like trucks and buses.
Limitations: Complex and costly to maintain.
Electro-Hydraulic Booster
This system combines electronic control with hydraulic pressure assistance to create a more optimal and responsive braking system.
Advantages: This advanced braking system provides enhanced control and responsiveness.
Limitations: Costly and complex, making it more common in premium cars.