a Flashcards
a (26 cards)
When parking, you should not use the parking brake if:
The brakes are very hot.
Hot brakes may not hold effectively, leading to vehicle movement.
During a walk-around inspection, ensure there are no cracks on the brake drums that are more than ____ of the width of the friction area.
One half.
Cracks exceeding this size can compromise brake performance.
When starting an engine, oil pressure should come up to a normal level:
Within seconds.
Quick oil pressure rise indicates proper lubrication.
A ____ allows a driver to gradually apply spring brakes.
Modulating control valve.
This valve provides better control over brake application.
Air storage tanks:
Hold compressed air for the brakes.
These tanks are essential for the operation of air brake systems.
During a static leakage test, the maximum leakage rate for a triple combination vehicle with air brakes is ____ in a minute.
5 psi.
Exceeding this limit indicates potential leaks in the system.
An air compressor governor controls:
When the air compressor pumps air into the air storage tanks.
Proper function of the governor is critical for maintaining air pressure.
A modulating control valve can control the:
Spring brakes.
This allows for more precise braking actions.
When in heavy traffic, the safest driving speed is:
The same speed being driven by surrounding traffic.
Matching speed helps maintain safety and flow.
What do the two systems of a dual air brake system share?
An air compressor.
This design enhances safety by providing a backup system.
In a dual air brake system, air pressure should build from 85 to 100 psi within ____ seconds.
Timely pressure build-up is essential for brake functionality.
When driving in fog, rain, or snow, use:
Low beams.
Low beams reduce glare and improve visibility in adverse weather.
There are two traffic lanes moving in your direction. You are driving in the left lane and many vehicles are passing you on the right. If the driver behind you wishes to drive faster, you should:
Move into the right lane when it is safe.
This allows faster traffic to pass safely.
If you park facing uphill on a street with a curb, set the parking brake and:
Turn the front wheels away from the curb.
This prevents the vehicle from rolling into traffic.
When parking downhill:
Your wheels should be turned toward the curb.
This helps secure the vehicle and prevent rolling.
Containerized loads:
Generally, are used when freight is carried part of the way by rail or ship.
This method enhances efficiency in transportation.
Where would you find the shut-off valves?
In the rear of a trailer.
Shut-off valves are critical for controlling the flow of materials.
Which of the following controls air in the service line?
The trailer hand brake.
It provides the driver with direct control over the braking system.
The driver’s hands should be at the ___ o’clock position on the steering wheel when operating a commercial vehicle.
9 and 3.
This position allows for maximum control and maneuverability.
Hydroplaning:
Is more likely with low tire pressure or something.
Maintaining proper tire pressure is crucial for traction.
For what types of fires is a B extinguisher applicable?
Electrical fires and burning liquids.
Understanding extinguisher types is vital for fire safety.
What could make a tire start burning?
Underinflated tires.
Proper tire maintenance is essential to prevent fires.
What does emergency braking mean?
Responding to a hazard by slowing the vehicle.
Quick response is critical for avoiding accidents.
During a pre-trip inspection, why is it important to have the starter switch key with you?
Another person could start the vehicle and move it.
This precaution helps prevent unauthorized use.
