Top 80 Air Brake Questions Minus Rows Flashcards
Oil and water usually collect in compressed air tanks. If you do not have an automatic tank drain, when should you drain the air tanks?
AFTER EVERY WORKING DAY
To check the slack adjusters on S-cam brakes, you should
PARK ON LEVEL GROUND, CHOCK THE WHEELS, AND RELEASE THE PARKING BRAKES.
The safety valve is set to automatically reduce pressure at _ psi.
150
If your truck has a properly functioning dual air brake system and minimum-size air tanks, the air pressure should build from 85 to 100 psi within _ seconds.
45
During normal driving, spring brakes are usually held back by
AIR PRESSURE.
The driver must be able to see a warning before the pressure in the service air tanks falls below _ psi.
60
Excessive use of the service brakes results in over-heating, which can lead to
EXPANSION OF THE BRAKE DRUMS.
When you are going down a long or steep grade after selecting the proper gear, the proper method of braking is to brake until your speed is about_ miles per hour below your safe speed and then release your brakes.
5
The air brake lag distance at 55 mph on dry pavement adds about_ feet.
32
How can you check the slack adjusters?
PARK ON LEVEL GROUND, TURN OFF THE PARKING BRAKES, AND PULL HARD ON EACH SLACK ADJUSTER. IT SHOULDNT MOVE MORE THAN ONE INCH.
The total stopping distance for air brakes is longer than that for hydraulic brakes because of
BRAKE LAG.
Repeatedly pressing and releasing (fanning) the brake pedal may result in
A LOSS OF BRAKE AIR PRESSURE.
The parking or emergency brake on a heavy vehicle can only be held in position by something that cannot leak away, like
SPRING PRESSURE.
Air braking takes more time than hydraulic braking because air
TAKES MORE TIME TO FLOW THROUGH THE LINES THAN HYDRAULIC FLUID.
When you apply the brakes, the brake shoes/linings are pressed against the
BRAKE DRUM.
It is not safe to drive a vehicle that has brake drums with cracks that are longer than _ of the width of the friction area.
1/2
The emergency brake system uses
PARTS OF THE SERVICE BRAKE AND PARKING BRAKE SYSTEMS TO STOP THE VEHICLE IN THE EVENT OF A BRAKE SYSTEM FAILURE.
What is a dual air brake system?
A TWO-BRAKE SYSTEM: ONE BRAKE OPERATES THE FRONT BRAKES, AND ONE OPERATES THE BACK BRAKES.
Before starting down a hill, you should be in the proper gear
SO YOU ONLY HAVE TO APPLY THE BRAKE JUST HARD ENOUGH TO FEEL A DEFINITE SLOWDOWN.
The driver must be able to see a low pressure warning, which comes on before pressure in the service air tank falls below _ psi.
60
Modern air brake systems are three different systems combined: the service brakes, parking brakes, and ___ brakes.
EMERGENCY
The air supply pressure gauge shows how much pressure
IS IN THE AIR TANKS.
The parking or emergency brakes of trucks or buses can legally be held on by __ pressure.
SPRING
The stop light switch
TURNS ON THE BRAKE LIGHTS TO WARN DRIVERS BEHIND YOU.
With air brake equipped vehicles, the parking brakes should be used whenever
YOU LEAVE THE VEHICLE UNATTENDED.
For air brake systems in good condition, the air compressor should start pumping at about_ psi.
100
An air brake system is fully charged at _ psi.
125
The air compressor governor controls
WHEN AIR IS PUMPED INTO THE AIR STORAGE TANKS.
If your vehicle has an alcohol evaporator, every day during cold weather, you should
CHECK AND FILL THE ALCOHOL LEVEL
Emergency controlled braking is when you
APPLY THE BRAKES AS HARD AS YOU CAN WITHOUT LOCKING THE WHEELS.
Water should be drained from the compressed air tanks because water can
FREEZE IN COLD WEATHER AND CAUSE BRAKE FAILURE.
What is the danger of non-functioning low pressure warning signal?
THIS COULD CAUSE SUDDEN EMERGENCY BRAKING IN A SINGLE CIRCUIT AIR SYSTEM.