Air brakes or Hydraulic brakes?

What is the difference in mechanism between hydraulic oil brakes and air brakes? What are the advantages of each? Which models are both applicable to, and what are the differences in terms of maintenance.


First of all, let's understand the difference between hydraulic brake and air brake in terms of structure.  The structure of hydraulic brake is relatively simple. The components are brake master cylinder, sub cylinder, oil cup and Connecting pipelines, etc., which also makes its installation space smaller and suitable for small vehicles.


In contrast, the structure of the air brake is more complicated, consisting of brake master cylinder, sub-cylinder, brake pipeline, air pump, air storage tank, high-pressure controller, relay valve and other components. It requires a large installation space and is suitable for medium and large vehicles. However, in recent years, many light truck models have been equipped with air brakes.


At the same time, there are also obvious differences in the braking medium, which can be seen from the names of the two. The braking medium used in the hydraulic brake is special brake oil, which is released through the oil during operation. Push the brake shoes to work. The air brake uses air. After pressurization, the brake shoes are pushed to work. If the air pressure is insufficient, there will be no braking force.


In addition, in terms of parking brake, the two also have some differences.  The parking brake under the hydraulic brake structure applies the braking force to the wheels by pulling up the parking brake handle. This is not the case with ordinary air brake parking brakes. It is a central disc brake, and the braking torque acts directly on the drive shaft, which also makes it only available when the vehicle is stationary.


Moreover, under the air brake structure, there is also a widely used parking brake form - air brake. The air cut-off brake is essentially different from the ordinary air brake parking brake. First, the air cut-off brake system is in the normal braking state through the strong spring. When the vehicle needs to drive, it needs to push the spring open through pressurized air. At this time, the braking state is in contact.

This is why models equipped with air brakes must start the vehicle in advance before releasing the parking brake. Also because of its unique design structure, the braking force and braking safety of the air brake are far greater than that of the ordinary air brake parking brake.


Due to the simple structure and small installation space, hydraulic brakes are often used on small-tonnage (passenger cars and small micro-trucks, etc.) models.


Air brakes are mostly assembled on medium and heavy trucks and heavy-duty buses. However, in recent years, it is often seen on small and light trucks. It is characterized by fast braking response and short braking distance, but the structure is complicated. Maintenance and purchase cost more, and the probability of long-term braking performance degradation is lower. And most of them are mainly used in conjunction with the air brake.


So when buying a vehicle, which braking system should you choose? First of all, medium and heavy trucks are equipped with air brakes as standard. There is no need to think about this. Most truckers struggle with small and micro trucks and light trucks. Compared with trucks, you can decide according to your daily operation scenarios.

If you drive more on high-speed, intercity or complex roads (with many slopes and sharp bends) and have a large transport capacity, it is recommended that you buy an air brake model, which will greatly improve the braking safety.

No matter which type of braking model you choose, we need to take good care of it in daily use.