What I am posting here is actually pages 55 through 58 of Phil Jensen's book Building Model Trucks. The early part of the text on page 55 refers to adding the air and electrical connections between the truck and trailer.
There are some diagrams showing how to hinge the hood and add air lines for the wedge brakes on the Ford LN.The hinges are easy to make. Any scrap plastic can be used. The rod I used for my Ford is a thin brass tube. I hinged my hood following rhese instructions. I hope this info will help.
Also, this brake diagram is helpful for detailing the brakes on any of the kits amt has produced of White Motors products since they have wedge brake also.
White Road Boss any Autocar kit any White Freightliner kit Western Star Diamond Reo