Have you ever wondered what happens when you stomp on your brake pedal? Although manufacturers do everything they can to make the process as simple as possible, there's a surprising amount of complexity at work every time you stop your car. Each brake pedal press triggers several actions to help halt your vehicle smoothly, safely, and quickly.

Hydraulic brake fluid is the lifeblood of this system, and it's what carries out most of the heavy lifting. Issues with any part of your brake fluid system can dangerously degrade brake performance or even result in catastrophic brake failure. Understanding how these problems occur and how you can spot the symptoms is crucial to keeping your car driving safely.

The Hydraulic Braking System Explained

Disc braking systems use hydraulic fluid to actuate pistons in the calipers at each wheel. When you press on the pedal, these pistons push the brake pads against your disc rotors. This action creates friction that ultimately converts your car's motion into heat. Without sufficient pressure, the pistons could not extend, preventing your car from stopping at all.

There are two relatively independent hydraulic braking circuits for the front and rear wheels in a typical modern car. This design provides redundancy by preventing a loss of pressure from disabling the brakes at all four wheels. Instead, a failure in either circuit will still allow the car to maintain some amount of stopping power by using the wheels on the remaining brakes.

The master cylinder and brake booster are two more critical elements of modern braking systems. In simple designs, pushing on the brake pedal actuates a lever in the master cylinder, which acts as a pump for the brake fluid. Since this would typically require a considerable amount of force, the car's brake booster uses the vacuum created by the engine to make the pedal easier to press.

The Signs and Symptoms of Hydraulic Failures

Failures can occur at numerous places in the system. Common problems include master cylinder issues, leaks in either the hard or soft brake lines, and contaminated or burnt fluid. Anything that reduces the pressure in the system can lead to potentially severe problems on the road, however. Insufficient hydraulic pressure can quickly disable an entire braking circuit.

Early symptoms of issues with the system usually include a soft or "spongy" feel to the pedal. If you notice a change in how your brake pedal feels, schedule an appointment with a repair shop as soon as you can. Never attempt to drive your car if the pedal falls to the floor or has no resistance, as this can indicate significant brake fluid loss.

Brake fluid problems don't present the same dramatic squealing and grinding noises as worn-out rotors or pads, but they're potentially far more dangerous. Now that you understand the basics of your hydraulic basic system, don't neglect to repair issues as soon as you notice them.

Talk to a car brake repair professional to fix your brakes.