Never apply the brake pedal if your spring breaks are activated. Brakes can be damaged if they are subject to both springs and air pressure.

You should not apply the brake pedal if the spring brakes are activated. The brakes could be damaged if they are subjected to the force of air pressure and the springs at the same time.

If a tractor is equipped with an Anti-Lock Braking System (ABS) but the trailer is not, the risk of jackknifing will be reduced and the driver should still be able to maintain steering control. If only the trailer is equipped with ABS, it is less likely that the trailer will swing out to one side.

A dual air brake system is made up of two separate air brake systems. If there is an air leak in one system, it may not affect the other.

In vehicles with air brakes, the parking brake is controlled by a knob. The knob is pulled out to apply the brakes, and pushed in to release them.

A dual air brake system is made up of two separate air brake systems. The systems share a single set of brake controls, but each has its own air tanks, hoses, and lines.

If the air pressure warning light or buzzer comes on while you are driving, you should immediately stop and safely park the vehicle. This warning signal indicates that there is a problem in the air brake system that needs to be fixed.

Air storage tanks are used to hold compressed air. The number and size of air tanks in an air brake system varies among vehicles.

Before driving a vehicle with a dual air brake system, you should wait for the air compressor to build up at least 100 psi in both the primary and secondary systems.

An alcohol evaporator can help prevent ice from building up in an air brake system. In cold weather, the evaporator should be checked and refilled every day.

Using the brakes excessively will cause them to overheat, making them less effective. This is referred to as "fading."

If you are unsure if a trailer is equipped with an Anti-Lock Braking System (ABS), look under the vehicle for the electronic control unit and wheel speed sensor wires coming from the back of the brakes.

While driving, spring brakes are generally held in place by air pressure. If the air pressure gets low enough, the springs will activate the brakes.

The parking brake should be applied every time you park your vehicle.

Anti-Lock Braking Systems (ABS) are compatible with air braking systems. ABS helps maintain control of a vehicle and prevents the wheels from locking up during hard braking on slippery surfaces. ABS can still provide benefits even if is present on only one axle.

Compressed air in an air brake system usually contains a certain amount of water and compressor oil. The water and oil can damage the brakes if left to accumulate in the system. Manually operated air tank drains must be opened daily to remove this build-up.

When performing a static leakage test on a double combination vehicle with air brakes, the leakage rate should be no more than 3 psi in one minute. If air leaks from the air brake system at a quicker rate, the vehicle should not be driven because something likely needs to be repaired.

Some pre-1975 vehicles have a front brake limiting valve, which has "normal" and "slippery" settings. The idea behind these valves was to limit the air pressure available to the front brakes when driving on slippery surfaces, and thereby reduce the danger of a front-wheel skid. Studies have found that this is not actually a concern, so if your vehicle has a front brake limiting valve, leave it in the "normal" position.

Pressing and releasing the brake pedal unnecessarily can let air out faster than the compressor can replace it, reducing the available air pressure. If the air pressure in an air brake system gets too low, the brakes will no longer work.

Because air takes time to flow through the air lines to the brakes, air brakes cannot begin working instantly. There is often a brake lag of at least one-half of a second between the moment the brake pedal is pressed and the moment the brakes begin to work. On vehicles with hydraulic brakes, the brakes work instantly when the pedal is pressed.

The total stopping distance for vehicles equipped with air brakes is made up of four factors: perception distance, reaction distance, brake lag distance, and braking distance. When braking at a speed of 55 mph while driving on dry pavement, the brake lag can add around 32 feet to a vehicle's total stopping distance.

It is important to know the maximum air loss rate that is safe for your specific vehicle. A single vehicle with air brakes should have a leakage rate no higher than 3 psi in a minute during an applied leakage test.

In a vehicle with air brakes, the brake lights are activated when the brake pedal is pushed and air pressure moves an electric switch. With the application of air pressure, the switch will then turn on the brake lights.

A low air pressure warning signal is required in vehicles with air brakes. The warning light is usually red and may be accompanied by a buzzer.

Friction inside a brake drum is caused when the brake shoes and linings push against the inside of the drum. The friction in the drums will slow and stop the vehicle.