What should the hub seal NOT be doing according to pre-trip inspection standards?

During a pre-trip inspection, the hub seal should not be leaking oil. A leak indicates that the seal is compromised, which can lead to a loss of lubrication for the bearings and result in serious mechanical failure. Proper lubrication is crucial for the smooth operation of the wheel bearings, and any oil leak can not only cause the bearings to wear prematurely but may also lead to wheel seizure while driving. Therefore, ensuring that the hub seal is intact and not leaking is vital for the safety and functionality of the vehicle.

In contrast, the other conditions mentioned—being in good condition, secured tightly, and regularly inspected—are all essential aspects of maintaining the integrity of the hub and ensuring safe vehicle operation. These factors contribute to overall vehicle health and help prevent mechanical failures while on the road.