• There has been a recent cluster of spammers accessing BARFer accounts and posting spam. To safeguard your account, please consider changing your password. It would be even better to take the additional step of enabling 2 Factor Authentication (2FA) on your BARF account. Read more here.

Fork seal only weeps when parked?

N4teTheGreat

FknN8
Joined
Dec 5, 2009
Location
San Francisco
Moto(s)
2012 DRZ 400s, 2018 Ducati Hypermotard SP, 2008 KTM 950 SM
Name
Nathan
I'm going to try a seal saver on it in case this is just dirt buildup, but, it seems weird to me that the seal only weeps after the bike has been sitting for a few days. I noticed it weeping before my trip to Alaska, thoroughly wiped down the fork leg and it never returned for the 7000 or so miles of that trip. Then I rode it to Hawthrorne, no issue, yesterday I noticed oil around the seal after a quick ride. Popped the wiper off and some more oil followed it down the fork leg, but, after wiping that off and pumping the fork a bit, nothing more. Seems odd, or is that how a dying seal behaves?
 
Slow leak, I'd guess. Could be as simple as dirt build up, to a compromised seal, to a nicked tube.

Pumping the forks manually exerts very little pressure compared to the violence of hitting a pothole at speed.

Seal saver (or improvise one from a soda bottle) then go ride it hard, jump some curbs to check for dryness.

Worst case, order new seals, then open it all up to check the tube. The front tire may have flung rocks and marred the tube and its sharp edges cut your oil seal.d.jpg
 
I agree with ichabodnt650 check your tubes for a ding. I had two seals changed on my 2016 Multistrada under warranty. They really only leaked or I only notied it when the bike set a while.


Disclaimer, you rode a long ways without a major problem. Your Duc just wanted to let you know it was still a Duc.
 
Last edited:
I've had race bikes do that for a year with no issue. I'd wipe it off when prepping the bike for tech. The seal wouldn't leak one bit all day. Repeat next time at the track. The seals would eventually be replaced with a service, never having failed.
 
OP • starting off seems you have a very good understanding of how the fork seal works and how to clean any grime out of the seal.
if the fork tube has a stone ding/Nick use your index finger and slide it around on the tube. You can feel a smaller Nick than you can see.
- If the seals rubber has gone dead/hardening ; it’ll first show when there’s the least air pressure to flex the seal out, such as when a lot of the bikes weight is on the kickstand.
–————…
A slightly leaking fork seal is annoying, but doesn’t need immediate fix. If the seal starts leaking heavy, then it does need fixed. Watch the brake caliper and that it stays dry.
 
I'll say this though, I have about six fork seal jobs lined up at the shop and these things usually comes in big ol waves. I did three tank level sensors/thermistors last week! Otherwise, try the seal saver!
 
I'll say this though, I have about six fork seal jobs lined up at the shop and these things usually comes in big ol waves. I did three tank level sensors/thermistors last week! Otherwise, try the seal saver!
🤦‍♂️
Hopefully, bent shift forks is not the next wave.
 
I get a better cleaning job with the seal saver by popping the dust seal off first. When done, lube the dust seal with grease and smear a little on top of the fork seal and then pop the dust seal back on.
 
Good info here, thanks all! It was weeping even before Alaska, so it was already being a Duc, and continues to be one :laughing seems likebeing on the kickstand and unweighted is the cause as it is the slightest weep. Forks and shock will be due for a service soon anyway, so I'll try the seal saver and keep an eye on it. I do not have the space / skills to remove the forks and shock myself so it'll be a bit more spendy when the time comes for service. I will check again today but I haven't noticed any nicks of the fork in previous inspections.
 
I’ll post a wildcat flyer of an idea. If the seal has hardened and is the cause of the leak/\you’ve lost some fluid.
Bio diesel is known to soften and swell seals; add some bio diesel to the fork hydraulics.
… a flyer guess add 5 cc of 100% bio diesel-into the leaky fork tube.
 
I believe the seal is only a few years old, so probably not hardened so either dirt or a nick in the fork tube, which I hop is not the case as I suspect a new Ohlins fork tube would be spendy...
 
I suspect a new Ohlins fork tube would be spendy

If there is a nick, run fingernail tip along the tube to feel/find it.

It is not always necessary to replace a nicked tube, you just need to soften the sharp edges if that's what tore your old seal. I used 500-grit then 1,000 grit sandpaper until I can no longer feel any edge catch my fingernail tip. Replaced new seal, filled oil, bolted back on. That was 16,000 miles ago. It held.

Pxl3_20230522_161346.jpg
 
I routinely take a flat Jewelers file and lightly wear down the high points of
the nick or scratch until it can no longer damage the seal... a slight
depression in the chrome surface is OK... the worst that can happen is when the
seal passes over the spot a small amount of fluid will fill the void... not
enough to worry about and better than replacing a leg every time a rock ding
happens...
 
We can close the thread, this is the answer right here, guess I need to do another road trip, it's the bike that is addicted, not me.
 
If that is true,
My Triumph, was really sad when I tore her down winter '22/'23. Remember the rains ??
My TW is really sad now, I tore her down in August.
Front end rebuilds
 

Attachments

  • IMG_6423.jpg
    IMG_6423.jpg
    107.5 KB · Views: 1
put the bike on stands, loosen the offending legs triple clamp bolts. Rotate the upper 90 degrees (or 180). Button it back up....

If your fork tube has a nick it will leak more, if the seal is just weeping because of some odd external factor this may take care of it.
 
Weeping fork oil evaporates when riding. Accumulates when you don't. Thus, it is crying...of a sort.

Clean/sand forks, even a hard exoskeleton of a dead bug can cause an issue.

Lastly, one of these saved me replacing/repairing a weepy seal: Fix leaky seal tip
 
Back
Top