Truck Brake Systems Overview in Philadelphia

Out of all of the pieces of equipment on a car or truck – including the steering wheel, engine, and wheels – probably the most important when it comes to preventing a crash in Philadelphia is the braking system. This is especially prevalent on trucks or tractor trailers, which are far heavier than normal cars, weighing more than ten times that of a normal passenger car even when empty. This additional weight makes it more difficult for the truck driver to slow the truck down or bring it to a stop in order to avoid a truck accident. These accidents, unfortunately, are far more dangerous for the cars that get hit than they are for the truck that hits them: According to the Insurance Institute for Highway Safety, 97% of the fatalities in truck accidents involving a large truck and a car happened in the car.

This makes the truck's braking system all the more important.

A Truck's Braking System

Technically, trucks and tractor trailers have three distinct braking systems: The service brake, the parking brake, and the emergency brake. The parking brake and the emergency brake, however, utilize the same equipment, with the only difference being when they are activated.

Here is how each one works.

The Service Brake

A truck's service braking system is the one that a truck driver uses the most often, by far. Just like in a regular passenger vehicle, a truck's service brake is activated by pressing the brake pedal located next to the accelerator, under the vehicle's dashboard and its steering column.

However, many of the other aspects of a truck's service brake system is much different than in a regular car.

The main difference is that a car's service brakes are hydraulic brakes, while a truck's service brake system is an air brake. Therefore, a car's brake utilizes braking fluid and needs a healthy supply of it in the car's brake lines in order to bring the car to a stop. A truck's service brakes, on the other hand, uses pressurized air. This difference has both pros and cons for a truck and those depending on its ability to stop.

The air brake system that most trucks use takes pressurized air from the pistons of the truck's engine compartment and runs it through the air lines that lace the undercarriage of the truck, bringing that pressurized air to the braking system in each wheel. When the pressurized air gets there, it starts a mechanical chain reaction that ends with the brake pads being applied to the rotating wheel, bringing the wheel, and therefore the truck, to a stop. The particular details of the mechanical chain reaction depend on which type of brake the truck uses on its wheels. While there are a handful of types of brakes, the two most common are the disc brake and the drum brake.

A truck that uses disc brakes sends pressurized air through the brake lines to the wheels. The inside of these wheels is attached to a rotor, which spins when the truck accelerates, making the wheel turn and the truck speed up. On opposite sides of the outside of the rotor, a caliper holds the brake pads in place. This caliper gets activated by the pressurized air from the engine compartment when the truck driver hits the brake pedal, squeezing the brake pads to the rotor and slowing both it and the attached wheel.

The other common kind of service brake that trucks use in the U.S. is a drum brake. This makes use of a brake drum, which is shaped like a flat rim that is attached to each one of the truck's wheels. This brake drum includes another flat rim, called the brake shoe. When the pressurized air from the truck's engine compartment enters the drum brake, it pushes the brake shoe outwards, until it comes into contact with the inside surface of the brake drum. Because the brake drum is attached to the truck's wheel, this contact slows the rotation of both the brake drum and the wheel, too, slowing the truck down.

Importantly, these truck braking systems all utilize pressurized air, rather than braking fluid. While this means the braking systems never run out of braking fluid, like a car's braking system can, it also means that there is a small delay from the time of the trucker hits the brakes to when the brakes begin to work. However, this delay is little more than a fraction of a second.

The Parking Brake

In addition to the service brake, a truck comes with a parking brake, as well. Much like in a regular car, this is a spring brake that is activated by pulling a lever in the truck's cab. Its main purpose is to provide a means of preventing the truck from moving while the engine is off.

The Emergency Brake

Finally, a truck is equipped with an emergency brake that is far stronger than its service brake, but which can cause the trucker to lose control of their vehicle and cause a jackknife or rollover accident. The emergency brake is typically the same thing as the parking brake but activated when the truck is in motion.

Philadelphia Truck Accident Attorneys at Gilman & Bedigian

Unfortunately, each and every one of these kinds of truck braking systems can wear out. When they do, it can put both the trucker and everyone else on the road in significant danger of a truck accident. These accidents tend to be far more serious for the other people on the highway: The size and height of a truck results in more force and significantly more damage being inflicted on the cars that have the misfortune to be involved in a truck crash.

This is why the personal injury attorneys at the law office of Gilman & Bedigian represent truck accident victims. By fighting for your rights and interests in court, we can get you the compensation you need and deserve. Contact us online or call us at (800) 529-6162 for a free consultation.

Let Us Help

If someone you are close to has been seriously injured or worse, you are naturally devastated not only by what has happened, but by the effect that the injury or loss has had on you and your family. At a time when you're vulnerable, traumatized and emotionally exhausted, you need a team that will support you through the often complex process that lies ahead.

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