both,there are two above each other, sins you noticed a leake, and you depress your pedal, this could make it act the same as a bad boom, and yes the nitragine does leak out after years. They are also real easy to replaice. But personally I would start first with the sencor, go to an auto store see if they may have a replaicement seal, if not just by a seal sheet and cut it out, ANY Leak bruce can and will give you the light as well.