To check if slack adjusters need adjustment, what should you do?

To determine if slack adjusters need adjustment, it is essential to release both the service and parking brakes. This process allows you to check the slack adjusters effectively while the brakes are not engaged, providing a more accurate assessment of the slack adjuster’s position.

When the brakes are released, you can visually inspect the slack adjuster for the proper amount of travel and ensure that it is functioning as designed. If the slack adjusters are out of adjustment, it can lead to braking problems, including uneven brake wear and reduced stopping power, which are critical for safe vehicle operation.

The other options do not provide a reliable method for checking slack adjuster adjustment. Activating the emergency brake could maintain pressure on the slack adjusters, making it impossible to evaluate them accurately. Checking brake light indicators does not relate directly to the mechanical condition or adjustment status of the slack adjusters. Similarly, while inspecting the brake pads visually can be important, it does not specifically assess the condition or adjustment of slack adjusters.