Utah CDL DMV Air Brakes 1

All trucks, truck tractors, and buses must be equipped with emergency brakes and parking brakes.

Before driving a vehicle with a dual air brake system, allow time for the air compressor to build up pressure of at least 100 psi in both the primary and secondary systems.

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.

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.

On vehicles with air brakes, a low air pressure warning signal will come on if the pressure in the air tanks falls below 60 psi. On large buses, the signal may activate at 80 to 85 psi.

Truck tractors with air brakes built on or after March 1, 1997, and other vehicles with air brakes built on or after March 1, 1998, must be equipped with anti-lock brakes.

Brakes can get out of adjustment quickly, especially if they are used to the point of overheating. Brake adjustment should be checked frequently.

If you use the parking brakes when the weather is very wet and the temperature is below freezing, the brakes may become frozen, preventing the vehicle from moving.

In general, a tank endorsement is required to a drive tank vehicle used to transport liquids or gases. This applies to both hazardous and non-hazardous materials.

In an air brake system, the air compressor governor controls when the air compressor pumps air into the storage tanks. It stops pumping if the pressure in the tanks becomes too high, and begins pumping if the pressure becomes too low.

If the low air pressure warning light turns on, you should stop and safely park your vehicle as soon as possible. Controlled braking will be possible only as long as enough air remains in the tanks.

If brakes are overused, they can become too hot. This overheating causes them to fade, making them less effective at slowing the vehicle.

Brakes are particularly prone to getting out out adjustment if they are hot. Use proper braking techniques to avoid letting your brakes overheat.

If brakes are used too much, they will overheat and become less effective. This is referred to as brake fade.

When performing a static leakage test on a triple combination vehicle with air brakes, the leakage rate should be no more than 5 psi in one minute. If the air leaks from the air brake system at a quicker rate, the vehicle should not be driven because something likely needs to be repaired.

In an air brake system, the air compressor governor controls when the air compressor pumps air into the air storage tanks.

It is important to know the maximum air loss rate that is safe for your specific vehicle. A double combination vehicle should have a leakage rate no higher than 4 psi in a minute during an applied leakage test.

A vehicle that is equipped with air brakes must also be equipped with a supply pressure gauge. This gauge tells the driver how much air pressure is in each of the vehicle's air tanks.

Before beginning a trip, it is important to check the brake drums during your walk-around inspection. It is unsafe to drive if any brake drum has a crack more than one half of the width of the friction area.

Anti-Lock Braking Systems (ABS) are compatible with air brakes and help a driver maintain control of their vehicle by preventing wheel lockup.

Tractors, trucks, and buses with Anti-Lock Braking Systems (ABS) have yellow malfunction lamps located on their instrument panels. Trailers have yellow ABS malfunction lamps on their left side, either on the front or rear corner.

In a newer vehicle with air brakes, the parking brake is controlled by a diamond-shaped yellow knob. The knob is pulled out to apply the parking brakes and pushed in to release them.

The method of controlled braking involves applying the brakes as hard as you can without locking the wheels. If you need to make large steering adjustments while using controlled braking, you should remove your foot from the brake pedal, steer, then reapply the brakes.

In an air brake system, the air storage tanks are equipped with drains to allow water and compressor oil to be removed. The water and oil can damage the brakes if left to accumulate in the system.

If used and maintained properly, air brakes are a safe and effective way to stop large, heavy vehicles.