We’re on our way to Scotland for a three week trip, slowly up through the Yorkshire Dales. After steep descents yellow brake wear symbol lights up. But after a few minutes goes out again. At first thought it was just one of those sensor issues. But it’s started to repeat. Brakes are performing fine, no squeaks or squeals. I guess they may need checking, but not a good time or place to do. Any thoughts??? Too decrepit to get wheels off and look myself. What period of warning do these indicators usually give before action is urgent???