CDL Combination Vehicles TestInspecting Combination VehiclesHard
A driver is performing a pre-trip inspection of a combination vehicle. They check the trailer's wheel ends and notice a small amount of oil leaking from the hub seal of one of the wheels. What is the most appropriate action to take?
- AClean the area and proceed, as a small leak is typically not a major concern.
- BTighten the lug nuts on the affected wheel to stop the leak.
- CHave the hub seal inspected and repaired before operating the vehicle.
- DAdd more oil to the hub and continue with the trip, monitoring the level.
Show answer & explanationAnswer & explanation
Correct answer: C. Have the hub seal inspected and repaired before operating the vehicle.
Any oil leak from a hub seal, even a small one, is a defect that can lead to significant problems. It indicates a compromised seal, which can result in lubricant loss, leading to wheel bearing failure, and can also contaminate brake components, reducing braking effectiveness. It must be addressed before operation.
Why the other options are wrong
- A. Cleaning the area only hides the problem; the leak will persist and could worsen, leading to unsafe conditions.
- B. Tightening lug nuts will not stop a hub seal leak; it addresses a different issue (loose wheel).
- D. Adding oil is a temporary measure and does not fix the underlying seal problem, which will continue to leak and cause issues.
Wheel End Leakage
Any visible leakage of oil or grease from a wheel hub seal or axle end cap is a critical defect that requires immediate attention and repair before vehicle operation.
- Indicates a compromised seal.
- Can lead to lubricant loss and wheel bearing failure.
- Can contaminate brake components, reducing braking effectiveness.
Memory trick: Oil leak, don't ignore; fix it now, or risk much more!