Why Do Semis Use Air Brakes Instead of Hydraulic Brakes?

Semitrucks require different braking systems than cars to stop the weight they carry.

Semitrucks are extremely heavy in comparison with passenger cars, especially when the trucks are pulling full loads in the attached trailer or trailers. The braking system chosen for most large vehicles is the air brake type.

Effects

Air brakes apply far more force than the hydraulic systems used in cars. The process of air compression, which involves engaging and disengaging the brakes when pressed, provides more assurance that the truck will stop than a hydraulic fluid system that can potentially leak and lose braking pressure.

Benefits

Air brakes are beneficial in that they do not have the inherent possibility of a hydraulic leak, as well as aiding in the attachment and detachment of the trailer or trailers being pulled.

Considerations

There are three parts to the air brake system: the parking, emergency and service brakes. The service brake is used when the brake pedal is pressed, and the parking brake works during application of the parking brake lever. The emergency brake engages both the parking and service brakes.

References

• Truck Accident Lawyers: Tractor Trailer Brakes