It sounds like the hood hinges are possibly worn out or need lubrication. If you can push down on the raised part of the hood and it seems to lay flush, this is likely the problem. Your model truck should have hinges that look like little spirals. These are generally very good hinges, and rarely fail, but will do exactly what you described when they need lubrication. Spray some WD-40 White Lithium Grease (https://www.amazon.com/Specialist-Lithiu...) on the hinges and then move the hood up and down a few times to work the grease in. This should solve your issue, good luck!