Air Brakes CDL Test - FREE Washington CDL Practice Test

1. _________ must have a low air pressure warning signal.

Vehicles with air brakes built after 2010
All vehicles with air brakes
Vehicles with air brakes built after 2005

2. If your tires are hot, you should NOT:

stop to let the tires cool down.
drive until you correct the cause of the overheating.
let air out of the tires so the pressure goes back to normal.

3. After a tire has been changed, the driver should stop a short while later to:

deflate the tire to 10 psi.
check the tightness of the nuts.
decrease tire pressure.

4. It is not safe to drive a vehicle that has brake drums with cracks that are longer than ___ the width of the friction area.

5. By pushing the trailer air supply control knob in, you:

supply the tires with air.
shut the air off and put on the trailer emergency brakes.
supply the trailer with air.

6. Why must air tanks be drained?

Water can freeze in cold weather and cause brake failure.
Water and oil reduce the air pressure.
To keep from fouling the air compressor oil.

7. The wig wag is:

a noise reduction mechanism.
a low air pressure warning system.
a type of rollover.

8. Supply pressure gauges tell drivers:

how much pressure is in the air tanks.
how much air pressure they are applying to the brakes.
All of the above.

9. Foundation brakes are used:

10. Front-end header boards:

should never be used.
protect drivers from cargo in case of an accident or emergency stop.
protect drivers from spilled cargo.

WA CDL AIR BRAKES PRACTICE TEST