Air Break practice Test Flashcards
The stop light switch:
Turns on your brake lights to warn drivers behind you
To test air service brakes, you should:
Brake firmly while slowly moving forward
If your vehicle has an alcohol evaporator, every day during cold weather you should:
Check and fill the alcohol level
The air loss for a straight truck or bus with the engine off and the brakes on should not be more than:
3 PSI in one minute
If your truck has a properly functioning dual air brake system and minimum size air tanks, the air pressure should build from 85 to 100 psi in ____ seconds:
45
A straight truck or bus air brake system should not leak at a rate greater than ___ psi per minute with the engine off and the brakes released:
2
Excessive use of the service brakes results in overheating which can lead to:
Expansion of the brake drums
The safety valve is set to automatically reduce tank pressure at what psi?
150
If you must make an emergency stop, you should brake so you:
Can steer and your vehicle stays in a straight line
The brake pedal in an air brake system:
Controls the air pressure applied to put on the brakes
straight truck or bus air brake system should not leak at a rate of more than ___ psi per minute with the engine off and brakes released:
2
To check the free play of manual slack adjusters on S cam brakes, you should park on:
Level ground, chock the wheels and release the brakes
The parking or emergency brake on a heavy vehicle can only be held in position by something that cannot leak away, like:
Spring pressure
Repeatedly partially releasing and pressing the brake pedal may result in:
A loss of brake air pressure
The brake system that applies and releases the brakes when the driver uses the brake pedal is the ____ brake system:
Service
The spring brakes on brake chambers on a straight truck will bring you to a stop when air pressure drops below ___ psi?
20
Which of these is NOT a proper time to apply the parking brakes
If you are going to use the parking brakes you need to make sure that they will hold the weight of the vehicle
If your truck or bus has a dual parking control valve, you can use pressure from a separate tank to:
Release the spring/parking brakes to move a short distance
The S-cam:
Forces the brake shoes against the inside of the brake drum
Under normal conditions, in order to engage the parking brakes, the driver:
Lets the air out of the brake system
The air compressor stops pumping air at what psi?
125
The braking power of the spring brakes:
Depends on the service brakes being in adjustment
If your vehicle has an alcohol evaporator, it is there to:
Reduce the risk of icing in air brake valves in cold weather
The air compressor governor controls:
When air is pumped into the air tanks
The braking power of the spring brakes:
Depends on the service brakes being in adjustment
