Why Do Semi Trucks Use Air Brakes?
It’s a sound you hear all over any major city and on highways everywhere: the unmistakeable hiss of air coming off of a big rig as it rolls to a stop next to you. But have you ever wondered: why do semi trucks use air brakes? Why can’t they use hydraulic brakes like smaller cars?
It all comes down to reliability and availability of resources. In general, the heavier the vehicle, the more likely it is to use air brakes. Hydraulic fluid for small car brake lines needs to be filled at a shop and maintained manually, while air is everywhere, ready to be used in any truck braking system. But that’s just one reason why they’re common in the industry.