UK PCV Theory Test Braking Systems and Technique 1

Question 1

What is the main advantage of a retarder on a large passenger-carrying vehicle?

Accepted Answer

It slows the vehicle using engine or transmission resistance, reducing heat build-up in the service brakes

Answer

It reduces tyre wear by replacing the foot brake entirely on level roads

Answer

It automatically applies the parking brake when the vehicle stops

Answer

It increases air pressure in the braking system during descents

Question 2

On a PCV fitted with an air braking system, what does a continuous drop in the air pressure gauge while stationary most likely indicate?

Accepted Answer

A significant air leak somewhere in the braking system

Answer

Normal compressor cycling between charges

Answer

The park brake has not been fully released

Answer

The ABS self-test is running

Question 3

Why does a fully laden PCV require a greater stopping distance than the same vehicle when empty?

Accepted Answer

Greater vehicle mass increases kinetic energy, requiring more braking force and distance to stop

Answer

The engine produces more exhaust back-pressure when loaded

Answer

Laden vehicles have lower tyre pressure, reducing grip

Answer

The ABS system is disabled above a certain weight threshold

Question 4

When should a PCV driver perform a brake check after setting off from a depot or after brake work has been carried out?

Accepted Answer

At a slow speed in a safe area as soon as possible after moving off

Answer

Only when the first passenger boards

Answer

After reaching the first bus stop on the route

Answer

At the end of the shift when the vehicle is returned

Question 5

What effect does driving through a deep ford or flood water have on a PCV's drum brakes?

Accepted Answer

Water can soak the brake linings, significantly reducing braking effectiveness until they dry out

Answer

It cools the drums and temporarily improves braking efficiency

Answer

It has no effect because drum brakes are sealed units

Answer

It increases air pressure in the braking circuit

Question 6

What is the correct procedure if a PCV driver experiences brake failure while moving?

Accepted Answer

Select a lower gear, use the retarder or exhaust brake, look for an escape route or runoff area, and use the parking brake progressively if needed

Answer

Immediately apply the parking brake at full force to stop quickly

Answer

Sound the horn and accelerate to clear other traffic before stopping

Answer

Switch off the engine to engage the mechanical stop lock