Free CDL Quiz

What are glad hands?

a.The hand grips on the trailer doors
b.Coupling devices that connect the air lines between the tractor and trailer
c.Safety chains used to secure the trailer
d.The handles used to crank the landing gear

Explanation

Glad hands are the coupling devices used to connect the air lines between the tractor and trailer. They connect the service (blue) and emergency/supply (red) air lines. They must be properly sealed and securely connected to prevent air leaks.

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Related Questions

At what PSI range does the tractor protection valve automatically close?What color is the emergency (supply) air line on a combination vehicle?What color is the service air line on a combination vehicle?What is the purpose of the tractor protection valve?What knob color is the trailer air supply control?

About the CDL Exam

The CDL (Commercial Driver License) exam tests your knowledge of commercial driving rules, safety procedures, and vehicle operation. You must score 80% or higher to pass the written knowledge test. The exam covers general knowledge, air brakes, combination vehicles, and various endorsements.

This question is from the CDL Combination Test #1 section. Practice with more questions from this category to build confidence before taking the official DMV test.

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