Air Brake Final Exam 30 Questions

The air loss rate for a straight truck or bus with the engine off and the brakes applied should not be more than:

D. 3 PSI in one minute

Which of the following statements about brakes is true?

A. The heavier a vehicle or faster it is moving, the more heat the brakes have to absorb to stop it.

The purpose of engine retarders is to:

B. Help slow the vehicle while driving and reduce brake wear.

If your vehicle has an alcohol evaporator, it is there to:

D. Reduce the risk of ice in air brake valves in cold weather.

The air supply pressure gauge shows the driver how much pressure;

B. Is available in the air tanks

Which brake system applies and releases the brake when the driver uses the brake pedal?

B. The service brake system.

When using the parking brakes or emergency brakes, what type of pressure is being used?

B. Spring pressure

There different systems are found on modern air brake systems: service brakes, the parking brakes and the:

A. Emergency Brakes

Air loss is a single vehicle (not a combination unit) should not be more than ______ with the engine off and the brakes on.

D. 3 PSI in one minute

The vehicle must have a warning device which comes on when air pressure in the service air tanks falls below:

C. 60 PSI

Air brakes equipped vehicles must have:

C. Air pressure gauge to show the pressure available for braking.

How do you check the free paly in manual slack adjusters?

B. Park on level ground and drain off air pressure before making adjustments.

The most common type of foundation brake found on heavy commercial vehicles is:

C. S-cam drum

The air compressor controls:

D. When the compressor will pump air into the storage tanks.

The brake pedal:

C. Controls the air pressure applied to operate the brakes.

What will determine how effective the spring emergency brakes or the parking brakes work?

C. Depends on the adjustment of the service brakes.

When a failure occurs in the service brake system, the system you need to stop the vehicle is the:

B. Emergency Brake System

If your vehicle is equipped with an alcohol evaporator everyday during winter weather you should:

A. Check and fill the alcohol level

What turns the electrical stop light switch in an air brake system?

C. Air pressure.

Which of the following is okay to find in the air brake system?

B. Air

If the air system should develop a leak, what will keep the air in the tanks?

D. The one-way check valve.

If your truck or bus has dual parking control valves, you can use pressure from a separate tank to:

A. Release the emergency brakes to move a short distance.

In air brake equipped vehicles, you use the parking brakes when?

C. Whenever you park the vehicle.

During normal operations, the parking & emergency brakes are usually held back by:

A. Air pressure.

A combination vehicle air brake systems cannot leak more than _____ PSI per minute with the engine off and the brakes released.

C. 3

A straight truck or bus air brake system cannot leak more than _____ PSI per minute with the engine off and the brakes released.

B. 2

You must make a quick emergency stop. You should break so you:

C. Can stay in a straight line and maintain steering control.

Why should you not fan the brakes on and off during long downgrades?

C. The short time off the brakes doesn’t allow brake cooling.

Which of the following answers is correct about using brakes on a long and/or steep downgrade?

A. Use the braking effects of the engine

To use the stab braking technique during emergency braking you: