Air Brakes Flashcards
1
Q
- The air compressor governor controls:
a. the speed of the air compressor.
b. air pressure applied to the brakes.
c. when the compressor will pump air into the storage tanks.
A
C
2
Q
- Modern air brake systems combine three different systems. They are the service brake, the parking brake and the: a. emergency brakes.
b. foot brakes.
c. S-cam brakes.
A
A
3
Q
- If the air compressor develops a leak, what keeps the air in the tank? a. the tractor protection valve.
b. the emergency relay valve.
c. the one way check valve.
A
C
4
Q
- Vehicles with air brakes must have:
a. at least two air tanks.
b. an air pressure gauge, to show the pressure available for braking.
c. an air use gauge, to show air used by the brake chambers for braking
A
B
5
Q
- A straight truck or bus air brake system cannot leak more than ____ per minute with the engine off and the brakes released. a. 1 psi
b. 2 psi c. 3 psi
A
B
6
Q
- During normal driving, parking and emergency brakes are usually held back by: a. air pressure.
b. spring pressure.
c. centrifugal force.
A
A
7
Q
- To check the free play in the manual slack adjusters, you need to:
a. stop on level ground and apply the parking brake.
b. park on level ground, chock the wheels and release the parking brake. c. apply the service brake by hand and watch the slack adjusters move.
A
B
8
Q
- The effectiveness of the spring brakes:
a. has nothing to do with the condition of the service brake. b. can only be tested by highly trained brake service people. c. depends on the adjustments of the service brakes.
A
C
9
Q
- Which of the following makes total stopping distance longer for air brakes than hydraulic? a. perception distance.
b. reaction distance.
c. brake lag.
A
C
10
Q
- The first thing to do when a low pressure warning comes on is: a. stop and safely park as soon as possible.
b. upshift.
c. open the air supply valve.
A
A
11
Q
- Air braking takes more time than hydraulic braking because air brakes: a. use different brake drums.
b. need to have air flow through the lines to work.
c. require heavier return springs.
A
B
12
Q
- Experts do not recommend fanning (on-again off-again braking) for long downhill runs because: a. air usage is less when fanning.
b. brake linings do not get hot when fanning.
c. the short time off the brakes does not allow the brakes to cool.
A
C
13
Q
- Oil and water that collects in air tanks can make brakes fail. If you do not have automatic tank drains, when should you drain the air tanks?
a. every other day. b. every day.
c. every week.
A
B
14
Q
- the driver must be able to see a warning that is given when air pressure in the service air tanks falls below:
a. 40 psi.
b. 50 psi.
c. 60 psi.
A
C
15
Q
- An air brake system safety relief valve opens at about:
a. 20 to 45 psi.
b. 120 psi.
c. 150 psi.
A
C