CDL Air Break Prep Flashcards
- During normal operations, the parking and emergency brakes are usually held back by
Air pressure
- Three different systems are found on modern air brake systems; service brakes, parking brakes, and the
Emergency brakes
- Air brake equipped vehicles must have
An air pressure gauge, to show the pressure available for braking
- A straight truck or bus air brake system cannot leak more than ______ psi per minute with the engine off and the brakes released.
2
- If your vehicle is equipped with an alcohol evaporator, every day during the winter weather you should
Check and fill the alcohol level
- Which of the following statements about brakes is true?
The heavier a vehicle or the faster it is moving, the more heat the brakes have to absorb to stop it
- When a failure occurs in the service brake system, the system you need to stop the vehicle is the
Emergency brake system
- Which of the following is O.K. to find in the air brake system?
Air
- The most common type of foundation brake found on heavy commercial vehicles is
S-cam drum
- You must make a quick emergency stop. You should brake so you
Can stay in a straight line and maintain steering control
- Which brake system applies and releases the brakes when the driver uses the brake pedal?
The service brake system
- What will determine how effective the spring emergency brakes or the parking brakes work?
The adjustment of the service brakes
- To use the stab braking technique during emergency braking, you
Brake hard with the pedal until the wheels lock, then get off the brakes until the wheels begin to roll again
- The air compressor governor controls
When the compressor will pump air into the storage tanks
- If your vehicle has an alcohol evaporator, it is there to
Reduce the risk of ice in the air brake valves in cold weather
- Why should you not fan the brakes on and off during long downgrades?
The short time off the brakes does not allow for brake cooling
- Air loss in a single vehicle (not a combination unit) should not be more than ______ with the engine off and the brakes on.
2 psi in one minute
- How do you check the free play in manual slack adjusters?
Park on level ground, chock wheels, release the parking brakes and pull slack adjusters
- A combination vehicle air brake system cannot leak more than ______ psi per minute with the engine off and the brakes released.
3
- The brake pedal
Controls the air pressure applied to operate the brakes
- The air loss rate for a straight truck or bus with the engine off and the brakes applied should not be more than
2 psi in one minute
- If your truck or bus has dual parking control valves, you can use pressure from a separate tank to
Release the emergency brakes to move a short distance
- The air supply pressure gauge shows the driver how much pressure
Is available in the air tanks
- Which of the following answers is most correct about using brakes on a long and/or steep downgrade?
Use the braking effects of the engine and when the vehicle speed reaches the “safe” speed, apply brakes firmly until vehicle speed is reduced to approximately 5 mph below “safe” speed
- The vehicle must have a warning device which comes on when the air pressure in the service air tanks falls below
60 psi
- In air brake equipped vehicles, you use the parking brakes when?
Whenever you park the vehicle
- What turns on the electrical stop light switch in an air brake system?
Air pressure
- When using the parking brakes or emergency brakes, what type of pressure is being used?
Spring pressure
- If the air system should develop a leak, what will keep the air in the air tanks?
The one-way check valve
- The purpose of engine retarders is to
Help slow the vehicle while driving and reduce brake wear
