The spring brakes used on the chambers in a straight truck will bring you to a stop when air pressure drops below ____ psi.
Answer: A
20
The spring brakes used on the chambers of a straight truck and tractor will activate below 45 psi, usually in the 20 to 30 psi range.
Source: Alaska CDL Manual
All choices
- A20
- B100
- C60
Why the other answers are wrong
B. 100
Choice B is wrong because 100 psi is above the activation range for spring brakes, which activate below 45 psi.
C. 60
Choice C is wrong because 60 psi is above the typical activation pressure range of 20 to 30 psi for spring brakes.
Alaska CDL Air Brakes Test Info
Questions on Exam
25
Passing Score
80%
Time Limit
Typically 30 minutes; varies by testing location
Age Requirements
Intrastate: 18+ · Interstate: 21+
Alaska Division of Motor Vehicles
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More CDL Air Brakes Practice Questions
- To check the free play of manual slack adjusters of S-cam brakes, you should park on:
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- Stab braking:
- Which procedure is used in controlled braking?
- Which braking technique may be used to stop quickly when you do not have ABS?