How Auto Inflation Systems work on Trailers

To identify whether your trailer is equipped with the auto-inflate system, look for the two air hoses extending from the axle hubs to the inflation valves of each tire. The tire inflation system draws air from the trailer tank when the tank's pressure reaches a minimum of 80 psi. A compact box mounted above the front axle contains the pressure monitor. If any tire is found to be underinflated, the system will supply the necessary amount of air to ensure proper inflation.

On the exterior of this box, you will find a valve that serves as an On/Off switch for the system. Familiarize yourself with the valve's position in the "Run" mode and ensure it has not been closed by someone. If a tire requires maintenance, the technician may turn off this valve and potentially forget to reactivate it. As a result, the system becomes disabled without your knowledge, which may lead to a tire being under the recommended PSI. Additionally, a white light is positioned on the front driver's side of the trailer. When connecting a trailer, this light can remain illuminated for a few minutes as the tire pressures equalize. However, if you observe the light still on while driving, it indicates a potential inflation issue, prompting you to pull over safely and inspect it.

Even with the auto inflate system, you can manually check tire pressure using a tire gauge. Unscrew the air hose where it connects to the hub and utilize your handheld air gauge to measure the pressure at the end of the hose, which features a valve similar to a regular valve stem. Then, refer to the tire sidewall for the proper inflation PSI, and always remember to give your tires a firm thump during your vehicle inspection.