Still on the heads but I noticed that the rubber cap that attaches to the head is cracked in a few places on the vertical cylinder. Doesn't seem to affect the integrity of the part but since the cracks run the length of the attach bolt holes I can see that over time it will be an issue. It bothers me but not so much that I cant let it go until the next belt change. Have any of you "fixed" this or is replacement the only option? I was thinking if there were a rubber type product that I could apply over the cracks to give strength and keep dirt out of the cracks that it might be beneficial. Thoughts?