🛞Arkansas Air Brakes — Question 4 of 10
What is the purpose of the modulating control valve (when equipped)?
Answer: C
To allow gradual application of the spring brakes when the service brakes fail.
When equipped, the modulating control valve allows the driver to gradually apply the spring brakes in the event of a service brake failure. Or if the service brakes have faded to the point that they will benefit from supplemental application of the spring brake.
Source: Arkansas CDL Manual
All choices
- ATo instantly apply the emergency brakes when air pressure is lost to the trailer.
- BTo balance air pressure between the truck and trailer brakes when the brake pedal is pressed.
- CTo allow gradual application of the spring brakes when the service brakes fail.
Arkansas 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+
Arkansas Department of Finance and Administration
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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:
- A slack adjuster free play needs to be adjusted if it is more than about ____ when you pull hard on it.
- Stab braking:
- Which procedure is used in controlled braking?
- Which braking technique may be used to stop quickly when you do not have ABS?