My dad recently picked up a 650 L with a ProCircuit T4 on it. He complains that it's very loud. He's going to be in town with the bike this weekend and I'm drafted to look at it. Does the T4 need an occasional repack? Seems to me there are a couple of tips available for the T4 -- maybe he needs a quiter one? Would there be a number on the tip somewhere? Any help is much appreciated.