There is no real magic to keeping your seals from leaking, but if anything really stands out it's to keep them clean! I came across these seal mate's at the parts store the other day. They are simply one way to get crud out that might be trapped between the seal and the fork tube. Even the smallest piece of debris can cause a leak. After inspecting my seals for any visible cracks or other visual problems, and measuring the amount of oil that had leaked, I decided that it wasn't worth replacing the seals quite yet, and to try a couple techniques first to get the slow leak I had to stop.
Another common issue is fork alignment. If the forks are not aligned the tubes will travel awkwardly causing additional stress and wear on the seals and guides. This Motion Pro alignment tool is a perfect way to make sure they are aligned.
On the fork leg I was having the most issues with, I actually removed the dust seal to make sure I could get to any crud that might be between the dust seal and the oil seal. After cleaning it, I put a bit of lithium grease in the cavity between the two to try to keep it clean and sealed.
I wanted to see just how much oil had leaked out over the last couple of years. I had a feeling it wasn't much, but it's really hard to tell unless you measure. A 32mm socket removes the cap so the old oil can be dumped out.
There is not much room here, but there is enough to dump the old oil out and replace it with new.
The fork oil capacity on a 2001 CR250 is 13 oz. or 383 cc. Here is the old oil from one leg in a 17 oz. water bottle. I am guessing I had somewhere around 12 oz. in each leg, so I was an oz. or so low after 2 years of use..not too bad. I use Bel Ray 10w fork oil. The cc's and oz. are listed on the size so it's easy to see how much you are pouring in.
As a final step to keeping crud out. I installed a neoprene "seal saver" on each leg. Hopefully these small steps will keep my seals alive for a while to come and avoid having to replace them if possible. The leak seems to have stopped for now. It's always important to clean your forks(and your entire bike for that matter) after each ride. These neoprene seal savers do pretty well unless the mud is dried on.
