I took my gooseneck trailer in to seek the advice of professionals at this store which probably saved me a flat on the highway. Valve stems wear out on trailers that sit out in the harsh elements and sun. Upon their recommendation I had good tires but needed new valve stems to avoid problems. For a 30 minute visit and very cheap bill, all 4 valve stems were replaced and I have logged over 3000 miles on the trailer recently with no mishaps.
They could easily have conned me into a set of tires, but were honest and as fair as they could be.
Definitely recommend!