Originally Posted by
pwhoever
When was the last time the right seal was replaced? If it's been a while, IMHO, I would consider doing both. If it's been 7k miles since both done, I would only do the left. One of the most common reasons that there is failure on left fork seals is that the anti dive valve has failed in the activated position and this causes too much pressure in that fork, and then it ends up leaking. What I did was add a shim so that even if I have a problem, it has no effect on the fork. In my case, I have Progressive Suspension fork springs so the ADV isn't even necessary. But I've been told that on trikes, the ADV valve isn't really necessary anyway, it's more important on the 2 wheeled GL1800's. Also check the upper tube really good to make sure that there are no nicks or excess dirt that can tear at the seal causing a leak.