Michigan CDL - Air Brakes Practice Exam

What is the proper procedure to inspect slack adjusters on S-cam brakes?

1. Chock the wheels and engage the parking brake

2. Park on a slope and disengage the parking brake

3. Check each slack adjuster after engaging the parking brake

4. Chock the wheels and disengage the parking brake

The correct answer is: Chock the wheels and disengage the parking brake

The correct approach to inspect slack adjusters on S-cam brakes is to first chock the wheels to prevent movement. This is a critical safety step that secures the vehicle, especially when the parking brake is disengaged. By disengaging the parking brake, you can properly assess the slack adjusters without the system being artificially engaged, which could give misleading results regarding their condition. When performing an inspection, you want to ensure that there is sufficient play in the slack adjusters as per manufacturer specifications. This step allows for a clear visibility and accessibility to each slack adjuster for a thorough check. Therefore, engaging the parking brake during this procedure is not advisable because it may restrict movement and provide an inaccurate assessment of how well the slack adjusters are functioning. Following these steps correctly contributes to safe vehicle operation, and proper slack adjuster functionality is crucial for effective braking performance.