Weeping Front Fork

I was cruising down the Interstate (nice song) when behold! Immediately in front of me is a very large and about 2" deep pothole. :cussing: With typical Phoenix traffic I had nowhere to move around, nor could I safely done so even if I tried because of the close proximity and my cruising speed of "around70 mph".

I backed off the throtle a tad, held on tight and hit straight on. That manuever worked and I never lost control or swayed, but I think I at least partially blew the fork seal on my right fork.

I say "partially", because although I now have a nice film of oil on my right fork, there is no dripping or spurting when I do hit a rut or run over baby cats or anything. (Just kidding about the cats. I should have said pigeons).

ANYWAY.... Is it possible the big jolt and fork slamming just caused a one time blow-by the seal and if I keep wiping, the oil film will slowly go away (and not because it's run out of oil)?

-OR-

An old trick in the hydraulics business is to put a teaspoon of Phospate Ester Fluid (like Skydrol which is a fire resistant fluid used in commercial aircraft hydraulic systems), or add a skosh and 1/2 of brake fluid to the oil. Neither of these fluids are compatible with Buna N seals (Nitrile) which is what is usually used for petroleum based fluids and adding a wee bit causes the seals to soften and swell just a bit. Too much and the seal gets too soft, just the right amount and it "renews" the seal.

Anyone out there have any thoughts as to whether it's a one time big burp, or if trying to soften the seal is a really a stupid idea? I figure if it doesn't work I would have had to rebuild/reseal the fork anyway.

Thanks in advance for you thoughts on this subject.

Thanks Cowboy. Since I like your answer I'll go with it and watch for awhile. I'll be out and about this weekend and will keep an eye on things.

Question 2: Assuming it was a one-shot burp, how can I tell how much oil to add, or should if I be concerned about that? The manuals I have don't mention "adding fluid" just changing and the amount used varies if they are "wet' or "dry" to start with. hmmmmmm

This is on a 1995 Sportster XLH883 by the way.

Thanks again!!

Thank you, chucktx.

Just watch your speed untill you're sure. My old Iron head got serious death wobbles when it got low on one side and I didn't know. I'd hate to hear about you on the news.

Thanks for some sage advise. I try to be always ready. Semper Paratus.

(I like your avatar):

your seal probably had a blow by and it might have folded your seal lip I would use some starting fluid to clean it and if it continues repair it if it stops as chuck said it is only ozs. so if it blew alot be concerned if just a little you get the idea.

Success at last

I also found where a rock or other street debris had hit my fork creating a "crater" in the chrome. (Glad it didn't hit me by the damage it did to hard chrome)!

It wasn't large but the "lip" around it couldn't have been doing much good to the seal. I carefuly stoned it down then polished the chrome with 200 grit emery paper and oil until there was barely a visible pin-point size depression.

I then drained the oil (a real exercise) and replaced it with straight 30 W oil. ( I got that idea off another forum). Contrary to the service manual, I got 10 fl oz out of the left fork (undamaged) and just a sly 9 out out the right one (the leaker). Manual says 9 fl oz "wet" but I added 8 fl oz mixed with 2 oz of engine seal renewer for a total of 10.
Replacing the top caps even with the forks fully extended on a M.C. jack is a real bitch! With the spring tension it took two of us and I had to spend some bucks to buy a 35mm socket.

It still wept on each subsequente ride, but each time it was less. After about 300 miles it's like new with no weapage and I really like the stiffer suspension with the 30W oil!

Some may not agree with this approach and I don't recommend it to anyone, but for me it will do until this winter when I plan to do some major service work including rebuilding the forks. On the other hand, If anyone is running anything different than the H-D "Fork Oil" (Transmission fluid)? it would be interesting to know to what and why you changed.