Z Endorsement Test - Quiz 02 (30) Flashcards
You should ascertain whether a trailer uses a spring brake or service brake priority system by…?
Asking your employer or a qualified person
The trailer supply valve is usually operated from the dashboard by a control with a knob of which color?
Red
Which of these can cause the air pressure to drop and so activate the spring brakes?
Any of them
a. Closing the trailer supply valve
b. A ruptured supply line
c. A disconnected supply line
Air brake systems on a trailer have which of these components?
Both of these:
a. Air tanks
b. Automatic spring brakes
What is a ‘gladhand’?
A coupling device
Which of these statements applies to spring brakes?
They are less powerful than service brakes
The tractor protection valve on towing vehicles is designed to do what?
Prevent air loss
Trailer hand valves can be used for…?
Normal braking
Trailer brake subsystems must apply the spring brakes automatically when the trailer supply line pressure drops below…?
414 kPa (60 psi)
In the majority of air brake systems, the parking and emergency brakes are applied by doing what to the control?
Pulling it out
A DD3 Safety Actuator has how many air line connections?
Three
Service line couplings are usually color coded which color?
Blue
The spring brake controls are normally what color?
Yellow
Trailer service brakes can be operated by…?
Either of these:
b. The brake pedal
c. A hand valve
When the tractor protection valve is opened, it allows air to…?
Flow to the trailer service line