One cause for seal leakage is not getting enough preload on the bearings during reassembly of the hubs. The inner nut on the load tube should be tightened very firmly, and then backed off just a little to allow the hub to be turned by hand with a slight amount of drag. Once the preload is set, the outer nut and the star-shaped lock washer maintains the proper preload. Failing to preload the bearings allows the hub to move up and down over bumps and keeps the seal from maintaining good contact with the sealing surface of the load tube.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
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