Boxerworks.com

. . . from the fill hole up top. Strange. I changed out the fluids when I put gaiters on the forks & replaced the hex fill plug, which a PO rounded out with a size too small Allen. The new plug is about a half inch longer than stock size. That said, I have a little weeping coming out top. Is there a crush washer or something I should know about? What other questions should I be asking?

Will swap fill plugs to see if, for any strange reason, the new one's to blame.

Do you have part #7 in this fiche?

If you have an allen-head bolt in your top nut that you can take out to add fork oil then someone has fitted the later version top nuts. (1978 on I think) Your model should have a nice chrome top cap that requires a pin spanner to remove, just like in Tims diagram. It wont fit the later top nuts.
Thats not the cause of your leak though,your allen bolt has to seal, you could try a fibre washer from a Auto parts shops. They should have something.

Later style fork cap, so you need 6 and 8 :

On the chrome cover, just use an O ring and don't tighten the cover more than hand tight.

Thanks all. I do have the setup on the 2nd fiche, with the black plastic caps on top. Apparently the small thin washer wasn't doing its job. With a little shaving down of the outer edge, the nylon washer seems to have done the trick. Thanks again. Everything's fine with the bike--no more driving to work!