Air Brake Test Air Brake Driving Techniques & Vehicle Control 2

Question 1

What is the recommended following distance for a truck with air brakes at highway speeds?

Accepted Answer

One second for every 10 feet of vehicle length

Answer

At least 4 seconds regardless of vehicle size

Answer

One car length per 10 mph of travel speed

Answer

Two seconds minimum at any speed

Question 2

What is 'air brake lag time'?

Accepted Answer

The delay between pressing the brake pedal and the brakes actually applying force

Answer

The time for air pressure to build from zero after starting the engine

Answer

The time needed to drain all air tanks after parking the vehicle

Answer

The delay before the low-pressure warning light activates in the cab

Question 3

Which three components combine to make up the total stopping distance for a truck with air brakes?

Accepted Answer

Perception/reaction distance + brake lag distance + actual braking distance

Answer

Tire wear distance + brake lag distance + vehicle length

Answer

Braking distance + vehicle length + following distance

Answer

Air build-up time + reaction distance + skid distance

Question 4

At 55 mph on dry pavement, approximately how many feet does a fully loaded large truck typically need to stop?

Accepted Answer

About 300 feet or more

Answer

About 100 feet

Answer

About 170 feet

Answer

About 230 feet

Question 5

Why can a fully loaded truck sometimes require more stopping distance than an empty truck?

Accepted Answer

Greater mass means more kinetic energy must be dissipated during braking

Answer

Loaded trucks always stop faster because the extra weight improves tire contact

Answer

Air brakes are mechanically less effective when carrying heavy loads

Answer

Loaded trucks require lower air pressure, which reduces braking force

Question 6

How does wet or icy pavement affect the stopping distance of a truck with air brakes?

Accepted Answer

It increases significantly due to reduced friction between tires and road

Answer

It decreases stopping distance because water cools the brakes

Answer

It remains the same if the driver applies the brakes correctly

Answer

It increases only slightly if the tires are in good condition