Difference Between Air Brake and Oil Brake

Air Brake vs Oil Brake
 

There are two main braking systems used in vehicles. Those are Air brake system and Oil (or hydraulic) brake system. Air brake uses air as the working medium and oil brakes use oil or hydraulic fluid as the working medium. Normally oil brake system is used for light vehicles such as cars, light duty trucks etc. Air brake system is used in trucks, buses, trains etc. Oil brake systems have some issues such as leakages; if the brake fluid leaks out, brakes will not work. However, both systems are being used in the automobile industry.

Oil Brake

Oil brakes can be found in light vehicles such as passenger cars. It uses oil or hydraulic fluid to operate the whole braking system. When the brake pedal is pushed, oil is pumped through the lines into the pistons mounted on wheels. This oil is stored in a cylinder. Based on the techniques used, oil brake can be categorized into two. Those are drum brake and disc brake. Drum brake is something like an old technique. Disc brake is the commonly used technique now. The disk brake system contains brake reservoir, master cylinder, brake lines, brake caliper, brake piston, brake pad and rotor. Reservoir contains the brake oil. Master cylinder is used to pump the required oil from the reservoir to the break lines. Oil is supplied through the lines. Brake caliper contains the pads and the piston, and it is on the rotor. Piston is pushed against the brake pads when it is fed with oil. Brake pads are griping the rotor, when the pedal is pushed. Breaking occurs due to the friction. Therefore, brake pads should be maintained continuously as they can wear out easily. Drum brake does not have brake pads; instead, it has break shoes.

Most importantly, you have to maintain the breaking system and not allow for any kind of leakage. Since oil is used, leakage can cause failures in the system. But modern oil brakes have leak-free couplers that prevent during uncoupling and coupling.

Air Brake

Air brake system has two technically different categories. Those are Direct Air Brake System and Triple-Valve Air Brake System. Direct air brake system use an air compressor to feed air through a pipe to the braking system. A triple-valve system has three main functions, as its name suggests. Those are charging, applying and releasing. At the charging stage, the air is pressurized. In that stage, the brakes do not release until the system is fully pressurized with air. This is a good concept for the safety of the vehicle. When the system reaches its operating pressure, the brakes are freed and ready to use. Brakes are applied at the applying stage, and the air is released at the releasing stage. When air is releasing, the pressure will decrease in the system. Due to this decrease, the valve opens, and new air will come in. The air pressure is the main technique used in this system. Air brakes have a lot of power. That is the main reason heavy vehicles like trains and trucks often use this kind of braking system. However, air can be expanded under cold conditions. This is somewhat a disadvantage seen in air brake system, which may lead to brake failure.