Section 1
You must stop your bus between:
A. 15 to 50 Feet before a railroad crossing
B. 5 to 10 Feet before a railroad crossing
C. 20 to 25 Feet before a railroad crossing
D. No answers are correct
A. 15 to 50 Feet before a railroad crossing
Stop your bus between 15 and 50 feet before railroad crossings. Listen and look in both directions for trains.
The air compressor governor controls:
A. The speed of the air compressor
B. Air pressure applied to the brakes
C. When air is pumped into the air brakes
C. When air is pumped into the air brakes
The governor controls when the air compressor will pump air into the air storage tanks. When air tank pressure rises to the "cut-out" level around 125 psi, the governor stops the compressor from pumping air. When the tank pressure falls to the "cut-in" pressure around 100 psi, the governor allows the compressor to start pumping again.
If your truck or bus has dual parking control valves it means that you can use pressure from a separate tank to:
A. Release the spring brakes to move a short distance
B. Apply more brake pressure if the main tank is getting low
C. Stay parked without using up service air pressure
A. Release the spring brakes to move a short distance
When main air pressure is lost, the spring brakes come on. Some vehicles have a separate air tank which can be used to release the spring brakes. This is so you can move the vehicle in an emergency.
Air loss in a straight truck or bus should not be more than _____ with the engine off and the brakes applied.
A. 1 psi in 30 seconds
B. 1 psi in one minute
C. 3 psi in one minute
C. 3 psi in one minute
With a fully-charged air system, turn off the engine, release the parking brake, and time the air pressure drop. The loss rate should be less than two psi in one minute for single vehicle brakes released, and three with the brakes applied.
Brake lag distance at 55 mph is _____ feet?
A. 50
B. 23
C. 32
C. 32
The air brake lag distance at 55 mph on dry pavement adds about 32 feet
You need to evacuate your bus in an emergency, passengers should be directed to a safe place no less than _____ feet from the bus.
A. 75
B. 100
C. 150
B. 100
Passengers should be moved at least 100 feet from the bus.
Of the choices below, the first thing to do when a low air pressure warning comes on is:
A. Stop and safely park as soon as possible
B. Up shift
C. Adjust the brake pedal for more travel
A. Stop and safely park as soon as possible
When the low air pressure warning light and buzzer first come on, bring the vehicle to a safe stop right away, while you can still control the brakes.
The brake pads should be _____ for the brakes to be on?
A. Worn 1/32 of an inch
B. Against the drum
C. Disconnection from the slack adjusters
D. Worn dangerously thin
B. Against the drum
To stop, the brake shoes and linings are pushed against the inside of the drum. This causes friction, which slows the vehicle.
What activates the stop switch?
A. Air pressure
B. Electrical
C. Mechanical force
A. Air pressure
Drivers behind you must be warned when you put your brakes on. The air brake system does this with an electric switch that works by air pressure. The switch turns on the brake lights when you put on the air brakes.
If your vehicle has an alcohol evaporator, it is there to:
A. Rid the wet tank of alcohol that condenses and sits at the bottom
B. Eliminate the need for daily tank draining
C. Reduce the risk of ice in the air brake valves in cold weather
C. Reduce the risk of ice in the air brake valves in cold weather
Some air brake systems have an alcohol evaporator to put alcohol into the air system. This helps to reduce the risk of ice in air brake valves and other parts during cold weather. Daily air tank drainage is still needed to get rid of water and oil.
Off tracking of the rear wheels is affected by:
A. Faster speed on turns and curves
B. Sharper turns and curves
C. Greater distance between the front and rear wheels
D. All answers are correct
D. All answers are correct
Off tracking can be changed by speed, the sharpness of the turn, and the distance between the front and rear wheels.
Air brake equipped vehicles must have:
A. An air usage gauge
B. A supply pressure gauge
C. At least two break heaters
B. A supply pressure gauge
All vehicles with air brakes have a pressure gauge connected to the air tank. If the vehicle has a dual air brake system, there will be a gauge for each half of the system.
You should know that your brakes are fading when:
A. You must push harder on the brake pedal to control your speed on a downgrade
B. The brake feels spongy when pressure is applied
C. Pressure on the brake pedal is released and speed increases
A. You must push harder on the brake pedal to control your speed on a downgrade
Increasing application pressure to hold the same speed means the brakes are fading.
A straight truck or bus air brake system should not leak at a rate of more than ____ psi per minute with the engine off and the brakes released.
A. 1
B. 2
C. 3
B. 2
With a fully-charged air system, turn off the engine, release the parking brake, and time the air pressure drop. The loss rate should be less than two psi in one minute for single vehicle brakes released, and three with the brakes applied.
What can legally hold a parking or emergency brake in position for a truck, truck tractor or bus?
A. Fluid pressure
B. Spring pressure
C. Air pressure
B. Spring pressure
All trucks, truck tractors, and buses must be equipped with emergency brakes and parking brakes. They must be held on by mechanical force because air pressure can eventually leak away. Spring brakes are usually used to meet these needs.
Your bus is disabled. The bus, with riders aboard, may be towed or pushed to a safe place only:
A. By another bus with its 4-way flashers on
B. By a tow truck with a GVWR of at least 27,000
C. If the distance is less than 1 mile
D. If getting off the bus would be riskier for the riders
D. If getting off the bus would be riskier for the riders
Do not tow or push a disabled bus with riders aboard the vehicle, unless getting off would be unsafe. Only tow or push the bus to the nearest safe spot to discharge passengers.
Modern air brake systems combines three different systems. They are the service brakes, the parking brakes and the:
A. Emergency brakes
B. Foot brakes
C. S-cam brakes
A. Emergency brakes
Air brakes are really three different braking systems: service brake, parking brake, and emergency brake.
The application pressure gauge shows the driver how much pressure:
A. Has been used on the trip
B. Is in the air tanks
C. Is being applied to the brakes
C. Is being applied to the brakes
Application Pressure Gauge shows how much air pressure you are applying to the brakes.
Vehicles with air brakes must have:
A. At least two air tanks
B. An air pressure gauge to show the pressure available for braking
C. An air pressure gauge to show air used by the brake chambers for braking
B. An air pressure gauge to show the pressure available for braking
All vehicles with air brakes have a pressure gauge connected to the air tank. If the vehicle has a dual air brake system, there will be a gauge for each half of the system.
The braking power of the spring brakes:
A. Increases when the service brakes are hot
B. Depends on the adjustment of the service brakes
C. Is not affected by the condition of the service brakes
B. Depends on the adjustment of the service brakes
The braking power of spring brakes depends on the brakes being in adjustment. If the brakes are not adjusted properly, neither the regular brakes nor the emergency/parking brakes will work right.
When driving at more than 40 mph, what is the safe minimum following distance for ideal daytime conditions?
A. One second for every 10 feet of vehicle length rounded upward
B. One second for every 10 feet of vehicle length rounded upward plus one second
C. Four seconds
B. One second for every 10 feet of vehicle length rounded upward plus one second
One good rule says you need at least one second for each 10 feet of vehicle length at speeds below 40 mph. At greater speeds, you must add 1 second for safety.
If you must make an emergency stop, you should brake so that you:
A. Can steer hard while braking hard
B. Use the full power of the brakes and lock them
C. Stay in a straight line and can steer
C. Stay in a straight line and can steer
You should brake in a way that will keep your vehicle in a straight line and allow you to turn if it becomes necessary. You can use the "controlled braking" method or the "stab braking" method.
If the air compressor should develop a leak, what keeps the air in the tanks?
A. The tractor protection valve
B. The emergency relay valve
C. The one-way check valve
C. The one-way check valve
Installed on the compressor side of the air tank is a one-way check valve, it allows air into the tanks, but does not allow it to flow back to the compressor.
Slack adjusters should not have any more than _____ of play?
A. 1/2 inch
B. 1 inch
C. 1-1/2 inches
B. 1 inch
Park on level ground and chock the wheels to prevent the vehicle from moving, release the parking brakes so you can move the slack adjusters, using gloves and pull hard on each slack adjuster that you can reach, and if a slack adjuster moves more than about one inch where the push rod attaches to it then adjustments are needed.
Which of the following should you do before leaving your vehicle unattended?
A. Set the parking brake
B. Remove the keys
C. Chock the wheels
D. Do all of the above
D. Do all of the above
Never leave your vehicle unattended without applying the parking brakes or chocking the wheels. Your vehicle might roll away and cause injury and damage