I was told that both the boot and the actual seal should be replaced, but that was after I only had the seal replaced since that's all I bought. The world's still turning so I guess it's okay to do just the seal ;) On another note, I would check that wherever you have it serviced, they have the proper equipment for holding the fork. Where I took mine, they wrapped it with a t-shirt and put it in a vise. Now I've got a marred up fork tube.