Low air pressure in the trailer's air tanks. The air tanks store the compressed air that is used to engage the brakes. If the air pressure in the tanks is too low, the brakes will not be able to engage. You can raise air pressure by releasing the air from the primary air tank and then filling it again with fresh air. This will ensure the brakes are able to be used with maximum force.
A problem with the brake actuator. The brake actuator is the device that converts the air pressure into mechanical force to engage the brakes. If the actuator is damaged, it will not be able to apply the brakes, even if there is enough air pressure in the system.
Improperly adjusted brakes. If the brakes are not properly adjusted, they will not be able to make contact with the drums and engage the brakes.
It is important to check the brakes and make sure they are in good working order regularly, especially if you will be using the trailer for long distances or in heavy traffic.
