Air Brakes - Quiz Sample #2, 15 questions
What are spring brakes?
Brakes used for slowing.
If the air supply is lost, springs inside the brake chambers activate to stop the vehicle.
The spring on the brake pedal.
When you apply your brakes, the air brake system works with an electric switch, by air pressure, to turn on the brake lights.
True
False
The service brake applies and releases:
The parking brake when you use the parking brake control.
The brake when you use the brake pedal during normal driving.
In the event of an emergency.
The parking brake applies and releases:
The brake pedal during normal driving.
In the event of an emergency.
The parking brakes when you use the parking brake control.
The emergency brake system:
Uses parts of the service and parking brake system to stop the vehicle in the event of a brake system failure.
Uses the service brake to stop the vehicle in the event of a brake system failure.
Uses the parking brake to stop the vehicle in the event of a brake system failure.
When the air pressure falls to the minimum pressure allowed in the system, the governor prevents more air from escaping the air tanks.
True
False
When you put the brakes on by pushing down on the brake pedal,
The air pressure is reduced to the brake pads.
Air pressure is applied to the brake pads.
Compressed air is let go out of the system.
The S-cam forces the brake shoes away from one another and presses them against the inside of the brake drum. It is called the S-cam because:
It is shaped like the letter “Z”.
It is shaped like the letter “N”.
It is shaped like the letter “S”.
What is a dual air brake system?
A two brake system, one operates the front brakes and one operates the back brakes.
A two brake system, one for each side of the vehicle.
A two brake system, one for daytime and one for nighttime driving.
Converter dollies built on or after March 1, 1998, are required to have anti-lock brakes. These dollies have:
A yellow malfunction lamp in the center of the dolly.
A yellow malfunction lamp on the right side of the dolly.
A yellow malfunction lamp on the left side of the dolly.
Which of these is the most important thing to remember about emergency braking?
Disconnecting the steering axle brakes will help keep your vehicle in a straight line during emergency braking.
Never do it without downshifting first.
If the wheels are skidding, you cannot control the vehicle.
Controlled braking:
Involves locking the wheels for short periods of time.
Can be used while you are turning sharply.
Is used to keep a vehicle in a straight line when braking.
To correct a drive-wheel braking skid, you should:
Increase braking.
Stop braking, turn quickly, and countersteer.
Increase braking, turn quickly, and countersteer.
How do you test the hydraulic brakes for leaks?
Drive slowly and pump the brake pedal. Make sure it doesn’t hit the floor.
Pump the brake pedal three times, then apply firm pressure to the pedal and hold for five seconds. The pedal should not move.
Drive 20 mph and slam on the brakes.
Modern air brake systems are three different systems combined together. They are the service, parking, and the ___ brakes.
Emergency
Foot
S-cam
The air supply pressure gauge shows how much pressure:
Is in the air tanks.
You have used in this trip.
Is going to the brake chambers.
The parking or emergency brakes of trucks or buses can legally be held on by ___ pressure.
Spring
Fluid
Air
Air brake equipped vehicles have:
An air use gauge.
An air supply pressure gauge.
A backup hydraulic system.
The stop light switch:
Turns on the brake lights to warn drivers behind you.
Tells you when you need to use your emergency brakes.
Tells you when the air brake system is low on air pressure.
The air loss rate for a straight truck or bus with the engine off and brakes on should not be more than:
1 PSI in one minute.
2 PSI in 45 seconds.
3 PSI in one minute.
With air brake vehicles, the parking brakes should be used:
Whenever you leave the vehicle unattended.
As little as possible.
Only during pre-trip and post-trip inspections.
The use of air brakes on a downgrade is only a supplement to the:
Use of the spring brakes.
Use of the front brake limiting valve.
Braking effect of the engine.
Excessive heat in the brakes can cause the:
Modulating control valve to wear out.
Brake lines to plug.
Brakes to fade or fail.
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 ___ mph.
25
35
30
If your bus or truck has dual parking control valves, you can use pressure from a separate tank to:
Balance the service brake system when you are parked.
Stay parked twice as long without using up service air pressure.
Release the spring emergency/parking brakes to move a short distance.
The modulating control valve allows you to control the:
Spring brakes.
Front brakes.
Amount of pressure in brake system.
Some air brake systems have an alcohol evaporator. What may happen if you don’t keep the unit filled with alcohol?
The S-cam may not rotate back when you release the brake pedal.
Ice may form in the air storage tanks and cause the brakes to fail.
Ice may form on the brake pads and warp them
Before driving a truck or bus with a dual air brake system, the pressure in each air brake system should be at least ____ PSI.
80
100
120
How should you check that the spring brakes come on when the air pressure in the system drops below a certain level?
Park on a slight incline, drain off air pressure, set parking brakes and check for movement.
Park on level ground, chock the wheels, release the parking brake when you have enough air pressure, shut the engine off, and repeatedly press and release the brake pedal.
Park on level ground, wait for normal air pressure, release the parking brake, move the truck forward slowly, and apply the brakes firmly using the brake pedal.
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