Being involved in a truck accident is one of the worst things that can happen to you on the roads of the United States. While car accidents are already dangerous enough – causing thousands of fatalities, hundreds of thousands of injuries, and millions of dollars in damage every single year – accidents involving trucks or tractor trailers are far worse. This is because trucks are higher off the ground, resulting in a collision that is higher up on the body of a typical passenger car, where there is less protection, and because a truck's weight is far more than the weight of a car. While cars typically weigh about 3,000 pounds, even empty tractor trailers regularly weigh close to ten times that, while trucks that are full of cargo weigh up to 80,000 pounds. Together, this additional height and weight make truck accidents much more dangerous for people who drive regular passenger vehicles.
Because of this danger, a truck's brake system is one of the most important pieces of machinery on the road. If it ever failed, the results are likely to be disastrous.
A Truck's Braking System
Trucks technically have three different braking systems. The service brake system is the one that is used the most often, and is activated when the truck driver presses the brake pedal underneath the steering column, right next to the gas pedal. The parking brake system prevents a stationary or parked truck from rolling down an incline. This is usually activated when the trucker lifts a lever in the center console of the cab, though the mechanism can also be found by the driver side door near the steering column in some trucks. Finally, the emergency brake system is almost never used. This is activated using the parking brake lever when the truck is in motion.
The Service Brake
The service brake on a truck is very different from a service brake on a regular passenger car. While a car's service brake is a hydraulic brake – which requires braking fluid to work properly – a truck's service brake is an air brake, using pressurized air to make the brake work.
This works by moving air, which has been pressurized in the engine, through the airlines to the braking system. Once there, the pressurized air works the mechanics inside the truck's particular type of brake.
One type of service brake is a disc brake. This uses a disc brake rotor, which is attached to the wheel of the truck, and brake pads, which are held by a caliper right next to the rotor. When the pressurized air enters this type of braking system, the brake pads squeeze the rotor, causing it – and the wheel it is attached to – to stop spinning, effectively bringing both to a stop.
The other common type of truck brake is a drum brake. This uses a brake drum, which is shaped like a flat rim and attached to the inside of each of the truck's wheels. Inside the brake drum is a similarly shaped brake shoe. When the pressurized air enters this type of braking system, the brake shoes get pushed outwards, into the inside of the brake drum. This causes both the brake drum and the attached wheel to come to a stop.
Because both of these common types of truck braking systems use pressurized air from the truck's engine, though, there is a slight delay of less than a second between the truck driver hitting the brakes and the brakes applying to the truck's wheels to slow them down. This is because it takes time for the pressurized air to move through the truck's airlines. However, one benefit of using air brakes rather than hydraulic ones is that air brakes do not rely on liquids like brake fluid to work. This means that truck brakes will not suddenly stop working if the brake fluid has run out, or if there is a hole in the brake fluid line.
The Parking Brake
Just like a normal car, trucks also have a parking brake. This uses a spring system, rather than pressurized air. In fact, when the parking brake is activated, it kills the air flow going through the truck's airlines. This allows it to be used when the engine is off, like when the truck is parked and turned off. However, because the parking brake is more powerful than the service brake system, it can be used in emergencies to help bring the truck to a halt.
The Emergency Brake System
The emergency brake system in a truck is the same spring system that the parking brake uses. When this is applied when the truck is in motion, though, it is called the emergency brake. Typically, air pressure in the airlines keeps emergency brakes from turning on. When this air pressure is not high enough, like when there are other mechanical issues or the air for the service brake system has run out, the emergency brakes take over and bring the truck to a stop. On the other hand, truckers can manually turn on the emergency brake by pulling the parking brake lever in the truck's cab. This is often done in a final attempt to get the truck to come to a stop before a collision, and can often result in the trucker losing control of the truck.
Maryland Truck Accident Attorneys at Gilman & Bedigian
While these braking systems are complex and highly effective in most situations, overuse, wear and tear, and a lack of maintenance can mean they stop working properly. This prevents truckers from bringing their massive vehicles to a stop before they cause a severe collision with your car, which can result in serious personal injuries to you or someone you love.
If this happens to you in Maryland, you need legal help. By representing you court, the personal injury attorneys at the law office of Gilman & Bedigian can protect your legal rights and interests. Contact us online or call us at (800) 529-6162 for a free consultation.