CDL Air Brakes

The emergency brakes are held by _____ force.

• Air.

• Heated.

• Compressed.

• Mechanical.

What may happen if brakes become too hot?

• Brake failure.

• Increased stopping distance.

• Air compressor failure.

• All of the above.

_____ are on the drum brakes between the push rod and S-cam.

• Push rod.

• Brake chamber.

• Castle nut.

• Slack adjusters.

An _____ helps prevent ice in air brake valves in cold weather.

• Alcohol Evaporator.

• Brake deicer.

• Air brake heater.

• None of the above.

How can you tell if your vehicle is equipped with an antilock braking system?

• Check if the vehicle was manufactured after 1998.

• Check if the vehicle was manufactured after 2000.

• Check if the vehicle was manufactured after 2010.

• ABS is still optional.

You are on a steep downgrade and have reached your safe speed of 40 mph. You would apply the service brakes until your speed drops to

• 25 mph

• 35 mph

• 30 mph

An antilock braking system (ABS)

• increases your normal braking capability.

• decreases your normal braking capability.

• activates when your wheels are about to lock up.

• shortens your stopping distance.

At what measurements is the safety valve USUALLY set to open?

• 150 psi

• 100 psi

• 200 psi

• 250 psi

The modular control valve enables the driver to ___.

• Rapidly apply the spring brakes.

• Slowly apply the spring brakes.

• Switch from spring to emergency brake.

• Deactivate the ABS.

When the pressure in the air tank rises to the "cut out" level, the air compressor governor will stop compressor from pumping air. This happens around:

• 170 psi

• 60 psi

• 125 psi

• Depends on the vehicle.