Braking Systems and Technique 1 Flashcards
6 cards from real PCV practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Braking Systems and Technique 1 flashcards as text
What is the main advantage of a retarder on a large passenger-carrying vehicle?
Answer: It slows the vehicle using engine or transmission resistance, reducing heat build-up in the service brakes
A retarder (hydraulic, electromagnetic, or engine-based) provides braking effort without using the friction brakes, preventing them from overheating on long descents and prolonging brake pad and drum life.
On a PCV fitted with an air braking system, what does a continuous drop in the air pressure gauge while stationary most likely indicate?
Answer: A significant air leak somewhere in the braking system
Air pressure should hold steady once the system is charged and the vehicle is stationary. A continuous drop points to a leak in pipes, valves, or connections that must be investigated before driving.
Why does a fully laden PCV require a greater stopping distance than the same vehicle when empty?
Answer: Greater vehicle mass increases kinetic energy, requiring more braking force and distance to stop
Kinetic energy increases with mass, so a heavier vehicle carries more energy that the brakes must dissipate. This directly increases the distance needed to stop at any given speed.
When should a PCV driver perform a brake check after setting off from a depot or after brake work has been carried out?
Answer: At a slow speed in a safe area as soon as possible after moving off
Checking brakes at low speed in a safe location immediately after moving off ensures any fault — such as a dragging brake or loss of air pressure — is detected before the vehicle enters traffic.
What effect does driving through a deep ford or flood water have on a PCV's drum brakes?
Answer: Water can soak the brake linings, significantly reducing braking effectiveness until they dry out
Water contaminating drum brake linings dramatically reduces friction, meaning the brakes may feel normal to apply but deliver far less stopping force. Drivers should test and dry brakes carefully after passing through water.
What is the correct procedure if a PCV driver experiences brake failure while moving?
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
Progressive downshifting and use of auxiliary retarders slow the vehicle while reducing brake reliance. A runoff area or escape lane provides a controlled stop. Slamming on the parking brake at speed can lock rear wheels and cause a skid or rollover.