CDL Vehicle Combination Practice Test

When connecting glad hands, aligning them at a 90-degree angle is essential for proper coupling of the air lines between a tractor and trailer. This angle allows for a secure fit, ensuring that the seals within the glad hands make full contact, which is critical for the air system to function correctly without leaks. A secure connection prevents air loss, which is vital for the operation of the trailer's braking system and other air-operated features. Selecting a 90-degree angle allows both hands to engage fully and helps in achieving the proper alignment needed for effective performance. A misalignment could compromise the integrity of the air connection, leading to potential safety hazards. Understanding this alignment technique is an important part of vehicle combination training, as it ensures that both drivers and vehicles operate safely and efficiently.