CDL Air Brakes TestInspecting Air Brake SystemsMedium
A driver is performing a pre-trip inspection and observes that the brake linings on a wheel are contaminated with oil or grease. What is the most significant consequence of this contamination?
- ADamage to the brake drum surface.
- BExcessive noise and squealing during braking.
- CReduced braking effectiveness and potential brake fade.
- DIncreased brake lining wear rate.
Show answer & explanationAnswer & explanation
Correct answer: C. Reduced braking effectiveness and potential brake fade.
Oil or grease contamination on brake linings significantly reduces the friction between the lining and the drum/rotor, leading to greatly reduced braking effectiveness. This can cause the brake to 'grab' unevenly or not at all, and can also lead to brake fade, where the brakes lose their stopping power due to heat.
Why the other options are wrong
- A. Damage to the drum can occur over time, but the immediate and most dangerous effect is the compromised braking performance.
- B. Noise can be a symptom, but it's secondary to the loss of braking power and not the 'most significant consequence'.
- D. While some wear might occur, the primary and most dangerous effect is the loss of friction, not just increased wear.
Brake Lining Contamination
Contamination of brake linings by oil, grease, or other fluids drastically reduces their friction coefficient, leading to poor braking performance and safety hazards.
- Common contaminants: oil, grease, brake fluid.
- Causes loss of friction.
- Results in reduced braking effectiveness and fade.
Memory trick: Greasy brakes mean no stop, just slide and a big drop!