Air Brake Practice Test

How do you examine the free play in manual slack adjusters?

1. Apply the service brakes manually to the brake chambers and wait as the slack adjusters shift.

2. Park on a uniform ground and remove air pressure prior to adjustment.

3. Park on a uniform ground, check the wheels, release parking brake and then pull the slack adjusters.

4. Stop on a uniform ground and apply emergency brakes.

The correct answer is: Park on a uniform ground, check the wheels, release parking brake and then pull the slack adjusters.

The correct approach to examining the free play in manual slack adjusters involves parking on a uniform ground, checking the wheels, releasing the parking brake, and then pulling the slack adjusters. This method ensures that the vehicle is stable and secured in a safe position, which is critical for accurate measurement and adjustment. By checking the wheels, you can confirm that there are no obstructions or issues affecting the wheel's movement and alignment, allowing for a proper assessment of the slack adjusters. Releasing the parking brake is essential because it allows the brakes to be in a fully released state while you perform the test, reducing any tension that could interfere with free play measurement. Pulling the slack adjusters gives you a direct way to assess how much free play is present and if adjustments are necessary to maintain optimal braking performance, preventing brake drag or excessive wear. Other methods mentioned, such as waiting for the slack adjusters to shift after applying service brakes or relying on emergency brakes, do not provide an accurate assessment of slack adjusters since they could be influenced by residual brake pressure or other factors, hiding any potential issues that need addressing.