One problem related to brake light on has been reported for the 2018 Ford Expedition. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2018 Ford Expedition based on all problems reported for the 2018 Expedition.
Under warranty, moisture was present in all the rear brake lights. The upper (third) brake light had the most condensation. An authorized Ford dealer reviewed the issue and advised Ford does not cover moisture within a light as the moisture will dissipate over time. I advised the upper brake light was never dry, they insisted warranty would not cover the issue. I could replace the light, I received a quote at that time. Now the upper brake light has less than 2 led's working and the visibility is next to nothing. Reviewing forums, this is an issue that has been present in the Ford Expeditions since the new vehicle design change. My concern is very simple, that brake light is important in the safety of our passengers, those around the vehicle and the vehicle itself. We have not been in a rear end collision with this vehicle, but it is difficult to see braking of this vehicle ahead when the vehicle is one car ahead of you based on what I have seen when driving behind this vehicle myself. I consider this brake light a significant component of the safety features in our vehicle. Timing of the issue was over a period of time. First phase was moisture not dissipating, second phase has been the led lighting continues to stop working, a few led's at first, now only a few are operational, and dim at best due to the continued moisture in the upper rear brake light assembly.