What Kind of Brakes Do Large Trucks Have?

close up of brake pads on large truck

Unlike passenger cars, semi-trucks rely primarily on air brakes, a powerful system designed to handle tractor-trailers’ immense weight and momentum. Air brakes on semi-trucks use compressed air to activate the brakes. With so much riding on these crucial safety systems, it’s essential to understand how air brakes function, their key components, and what happens when semi-truck brakes fail.

Key Components of Air Brake Systems

Air brakes are complex mechanical systems with five key components:

  • Compressors, which generate the air supply used to power the system
  • Air tanks or reservoirs to store compressed air
  • Brake chambers, which convert air pressure into mechanical force
  • Brake drums, which use friction from brake shoes to slow the vehicle down
  • Foot valves, which function as brake pedals for semi-truck drivers

Semi-truck braking systems are commonly referred to as “air brakes.” However, compressed-air brakes are just one of three interconnected systems:

  • Service brakes, which are like the brake pedals found on passenger cars
  • Parking brakes, which are spring brakes that are applied when parking on steep inclines or hills
  • Emergency brakes, a combination of the service and parking brakes

These three braking systems function as a series of backups. If one fails, the other semi-truck braking systems are engaged to ensure the vehicle can stop.

Different Characteristics of Truck Air Brakes Compared to Cars

The brakes used in passenger cars rely on hydraulic fluid to engage the brakes. While hydraulic brakes are less complicated to use and maintain, air brakes are very efficient at stopping a vehicle quickly.

Air brakes automatically engage in the event of air pressure loss, preventing runaway situations and enhancing safety. This combination of power and reliability makes air brakes the ideal choice for semi-trucking safety.

Other Types of Brakes on Semi-Trucks

In addition to air brakes, semi-trucks may utilize:

  • Jake brakes use the engine braking system to slow the truck. Jake brakes on semi-trucks are recognizable by a loud roaring sound.
  • Electric brakes are supplemental braking systems that help reduce the strain on long downgrades.
  • Disc brakes use brake pads to apply friction to discs on the wheels. They are usually more effective than drum brakes and less likely to fade.
  • Transmission brakes apply friction to the transmission shaft and are typically used with disc and drum brakes.

How Brake Problems Cause Truck Accidents

Even with multiple failsafes, semi-truck braking systems can malfunction in several ways. Some of the most common causes include:

  • Overheating due to excessive downhill braking
  • Lack of maintenance
  • Skipping regular inspections
  • Environmental factors like condensation can freeze air lines
  • Incorrect adjustments
  • Uneven brake wear
  • Loss of air pressure due to leaks

When any of these or other issues occur, the results can be catastrophic. Truck accidents caused by braking problems lead to a loss of driver control, jackknifing, and collisions.

How Our Truck Accident Lawyers Can Help After a Truck Crash Involving Brake Problems

If you have been injured in a semi-truck accident due to brake failure, you need experienced legal representation. At Morris, King & Hodge, P.C., in Northern Alabama, our truck accident lawyers understand these cases. We are ready to:

  1. Thoroughly investigate the truck accident to determine the cause and identify liable parties.
  2. Gather evidence, including maintenance records, driver logs, eyewitness accounts, and expert testimony.
  3. Negotiate with insurance companies to seek maximum compensation for your injuries and losses.
  4. Represent you in court if necessary to protect your rights.

Don’t face the aftermath of a semi-truck crash alone. If you got hurt in a truck accident caused by brake failure, contact Morris, King & Hodge, P.C., today for a free consultation. We’re here to help you get back on the road to recovery.

Joe A. King, Jr., has been trying cases on behalf of injured plaintiffs or surviving families since 2000.