How Does an Air Over Hydraulic Brake System Work?

While air over hydraulic brakes might not be the most common technology anymore, they are still relevant and thus important to understand.

In fact, a good understanding of air over hydraulics is important not only because of the necessary maintenance and upkeep, ut also in case you’re thinking of a replacement.

In this article, we will go through what an air over hydraulic brake system is, and how the system works.

What is an air over hydraulic brake system?

As the name suggests, this type of braking system is a combination of parts of an air brake system and a hydraulic brake system.

It uses both air and hydraulic compression to operate the brakes.

This type of braking system was created with the hopes of increasing the braking power compared to the power in a hydraulic braking system.

This system is not the most common, but it can often found in trucks, trailers, cranes, and other industrial equipment.

Because of all of their parts and components, these systems must be inspected often and maintained by a professional.

How it works

Normal braking

As we learned earlier, this system works by combining elements of an air brake and a hydraulic brake.

It has a special type of power cylinder that contains a hydraulic cylinder and an air cylinder in tandem.

While both of these cylinders have pistons, the important thing to note is that the pistons are not the same size. the air piston is greater in diameter compared to the piston for the hydraulic cylinder.

The air piston is greater in diameter compared to the piston for the hydraulic cylinder.

What does this mean? This means that there is more hydraulic pressure compared to air pressure during normal breaking.

So when the pedal is pressed, the valve opens and releases the pressure, which a causes braking to occur.

Hard braking

The valve movement when is different depending on how hard the brake pedal is pressed.

When heavier pressure is applied to the brake, there is more valve movement.

Because of the increased valve movement, a greater amount of pressure is released into the power cylinder, causing stronger and faster braking.

What to look out for

As we mentioned earlier, the many parts of this type of system means there are more areas that could be faulty or need repair.

You’ll need to be on top of the maintenance of the many parts of the air over hydraulic braking system, as any issues could result in liabilities and expensive repairs.

Besides the system itself, the oil involved in this system needs to be maintained. Be aware of potential freezing during the winter months!

Bottom Line

Hopefully, this article answered any questions you had about how an air over hydraulic brake system works.

There are many types of brakes, but it is still important to understand how each system works, especially if you have machinery that uses certain systems.

We have a lot of experience with a variety of braking systems and machinery, so if you have any questions or need any advice, feel free to contact us.

You can also leave us a question or a comment in the comment section below!

Posted in Industrial Brakes and Clutches.