Arizona Air Brakes CDL Practice Test

To check the slack adjusters on S-Cam brakes, you should...

1. Leave the parking brakes on and pull on the slack adjuster

2. Wear gloves and pull hard on each slack adjuster

3. Make sure the slack adjusters move more than one inch each way

4. Drain the air from the system and pull on the slack adjusters

The correct answer is: Wear gloves and pull hard on each slack adjuster

The correct approach for checking slack adjusters on S-Cam brakes involves pulling on each slack adjuster to assess their movement and function. This method allows you to determine whether the slack adjusters are engaging properly and ensuring that the brake system has the necessary tension to function correctly. When pulling on the slack adjuster, it is vital to ensure that you are wearing gloves to protect your hands, as the components can be rugged and potentially have sharp edges. In this task, it is essential to ensure the brakes are not engaged, so leaving the parking brakes on or draining the air from the system would not provide the proper conditions to check the slack adjusters — attempting to carry out the test under these conditions could lead to inaccurate assessments. Furthermore, checking for more than one inch of movement is not a reliable standard for assessing the effectiveness of the slack adjusters, as they should ideally have limited movement when functioning correctly. Taking these precautions and using the correct method to assess slack adjusters ensures the safety and reliability of the brake system in your vehicle.