Truck and trailer tips - How to maintain your truck and semi trailer? A customer in Ghana bought our flatbed semi trailer    New Truck and Trailer Maintenance: 1. Before the new trailer is used for the first time, we should check it according to the "instructions for use" and tighten all external bolts and nuts. 2. Within the first 300 kilometers of a new trailer, its components are in a running state. During this period, the weight of the trailer should not exceed 80% of the rated load......