I too have used lots of crush washers over and over. Usually it is the SECOND crush washer on the bike. The first one, installed by the dealer, is usually, well, crushed. That is, after all, what they do. And it is crushed because some neandertal has decided to tighten it to the point where to remove it I need to pound on the end of the wrench with a rubber hammer to free it. After that fiasco I put a new one on, tighten it 'til it just snugs and give it a little mild tug. They last a long time if you don't overtorque them. And, no, they don't leak.........
Monte
