Ultegra brake hood problem?

My right brake hood seems to vibrate all the time like it is loose when you apply the brake–alot of play compared to the left. Any help?

I seem to remember reading that the little plastic caps rattle on some of the older Ultegra STI shifters, but Shimano fixed this problem a few years back. Assuming that your problem is that you have one of the older models, I think it’s just a matter of getting the new plastic caps. Not positive, though.