CDL Air Brakes TestInspecting Air Brake SystemsEasy
A technician is inspecting the brake linings on a commercial vehicle with air brakes. They notice that the linings on one wheel are covered in grease or oil. What is the most significant consequence of this condition?
- AOverheating of the brake components.
- BReduced braking effectiveness for that wheel.
- CIncreased noise during braking.
- DAccelerated wear of the brake drum.
Show answer & explanationAnswer & explanation
Correct answer: B. Reduced braking effectiveness for that wheel.
Brake linings covered in grease or oil lose their friction properties. This significantly reduces the braking effectiveness of that wheel, potentially leading to uneven braking, longer stopping distances, and a loss of control.
Why the other options are wrong
- A. Overheating is more common with dragging brakes or excessive use; contaminated linings struggle to generate heat due to lack of friction.
- C. Contaminated linings might squeal, but reduced effectiveness is the primary safety concern.
- D. While possible long-term, the immediate and critical effect is on braking friction and effectiveness.
Brake Lining Contamination
Brake linings contaminated with grease, oil, or brake fluid lose their ability to create friction, severely reducing braking effectiveness.
- Sources include leaky wheel seals, brake fluid leaks, or improper lubrication.
- Contaminated linings must be replaced, and the source of the leak repaired.
- Results in reduced friction, uneven braking, and increased stopping distances.
- A critical safety defect requiring immediate attention.
Memory trick: Oily linings, slippery stops, a dangerous combo that drops.