Question 25 of 25
Score: 0/0At what air pressure range do the spring brakes on a tractor or straight truck fully engage?
ExplanationTractor and straight truck spring brakes automatically apply fully when air pressure falls within the 20 to 45 psi range to help stop the vehicle safely.
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Did you know? Know your PSI thresholds — when the warning activates and when the brakes apply automatically.
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