Louisiana Class D Chauffeur's License Practice Test

Which component must be checked for adjustment in S-cam brakes during an air brake check?

1. brake discs

2. manual slack adjusters

3. brake fluid reservoir

4. rotors

The correct answer is: manual slack adjusters

In S-cam braking systems, the manual slack adjusters play a crucial role in ensuring that the brakes operate effectively. These adjusters are responsible for maintaining the correct amount of slack in the brake system, allowing for proper brake function. If the slack adjusters are not correctly adjusted, it can result in inadequate or uneven braking, which can be dangerous. During an air brake check, it's essential to inspect the manual slack adjusters to ensure they are working correctly and have been properly adjusted to maintain the optimal distance between the brake shoes and the drum. This check helps prevent issues such as brake drag or reduced braking force, which can jeopardize safety on the road. The other components, like brake discs, the brake fluid reservoir, and rotors, are not specifically checked for adjustment in relation to the S-cam braking system. Instead, they may be part of different systems or have different maintenance checks that do not involve the manual adjustment of slack.