Sometimes a seal can leak just from being excessively dirty. I had this happen to my k10 forks. I had to figure out how to disassemble them by Googling so I could remove the lower fork seals, cleaned them real good, cleaned the fork legs and reassembled. Put the whole front end together, filled forks with oil, squeezed the front brake and pushed down on the handlebars hard and fast several times. Then took a paper towel and dabbed around the fork lowers where they'd been leaking. No more oil and have not had a problem with them since. As far as the springs are concerned, unless they are very badly rusted they should not have lost any strength, that simply doesn't happen, the springs are tempered and would only lose their temper through excessive heat or wear. The springs may be a little soft to begin with, the k10 fork springs are. But the springs are really just there to assist the travel action, the hydraulic cylinders actually do most of the work. The best thing to do is take the forks completely apart, clean them out thoroughly, use solvent if necessary and let sit to dry if solvent has been used. When you are ready to put them back together, fill with oil to the level recommended in the owners manual. Test the forks for leaks and to see how comfortable you are with the amount of travel. If there is too much travel, add another half ounce of oil to each fork leg and test again. When you're sure there are no leaks and the fork has the right amount of travel for you, you're good. Now obviously if you find anything broken or damaged when you take them apart, you'll need to replace it.