Illinois Pre-Trip Vehicle Inspection CDL Practice Test 2026 - Free CDL Practice Questions and Study Guide

Ensuring that the glad hands are locked in place and undamaged is crucial because they are responsible for connecting the air supply between the tractor and the trailer. A secure connection is necessary to maintain proper air pressure for the brake system, which is vital for safe operation. If the glad hands are not locked or are damaged, there is a risk of an air leak, leading to brake failure or other operational issues while driving. This safety measure is an important part of the pre-trip inspection, underlining the need for all components to be in good working order to avoid dangerous scenarios on the road.

The other options do not contribute to the primary function of the glad hands in maintaining vehicle safety and performance. Bright colors may improve visibility but do not affect their operational integrity. Easy removability is not a desirable quality for air connections that require a secure fit during driving. Disconnecting them for safety contradicts the purpose of their operation, which relies on them being properly connected.