What occurs if more than one-fourth of the leaf springs are leaking?

Answer: C — It will put the vehicle out of service

If more than one-fourth of the leaf springs are leaking, it indicates a significant failure in the vehicle's suspension system. Leaf springs are crucial for supporting the vehicle's weight and ensuring a smooth ride, so when a considerable portion is compromised, it can lead to unsafe driving conditions. Unable to maintain proper vehicle stability and control, this situation necessitates that the vehicle should be taken out of service immediately to prevent accidents or further damage. Therefore, putting the vehicle out of service ensures the safety of the driver and other road users while prioritizing the necessary repairs to restore safe operation.