Is it possible to add fork oil without removing forks ?

Joined
Aug 16, 2022
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Edmonton, Alberta
Had noticed a minor leak in one of my forks over winter. Got the tool for cleaning the fork seals, used it and the fork no longer seems to leak. Is there a way to top up the fork oil without removing the forks ? Thanks.
 
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There are ways to do it but as a purest, I like to remove, check and replace things.
You haven't said when the fork's internals were checked last (not a criticism) so hard to say what other issues the bike may have.

@Igofar - Larry, what's your opinion on the subject?
 
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Better question is how much oil did you lose? Even a weeping seal lets only a tiny bit out. I'd suggest you wait until winter and don't take the bike off the road during the riding season. If you cannot work on your bike in the winter, that's another point to consider. I tend to agree with @nicksacco - do it all since forks are often neglected. This will take more time than just adding a bit of oil to the dirty stuff in there now.

To answer your original question, yes it is possible to simply add a bit of oil.
 
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I don't have the bike or service manual in front of me, but I would imagine loosen top pinch bolt, remove fork cap carefully, add oil, reverse procedure. Seemingly minor differences in oil height in the fork makes a significant difference, I would be careful about overfilling. It can be difficult to measure oil level in cartridge forks besides filling them from dry with the desired volume.
 

Igofar

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There are ways to do it but as a purest, I like to remove, check and replace things.
You haven't said when the fork's internals were checked last (not a criticism) so hard to say what other issues the bike may have.

@Igofar - Larry, what's your opinion on the subject?
Sure, throw me under the bus :rofl1:
I'm not of the camp of using seal mates or 35mm film, to scrape/clean seals, as it does more damage than good.
When seals are installed on the tubes, you should use a condom or plastic film over the edge of the tube to protect the soft sealing edge of the seal from damage....
Yet, folks want to shove a hard piece of plastic down there and twist and scrape things etc. :doh1:
Since oil has been lost, the OP has no idea what damage/wear has been done to the bushings inside the tubes, or how much fluid has been lost etc.
Adding some, could unbalance the forks and cause handling issues.
The forks need to be removed, taken down, cleaned, and rebuilt correctly, if you want to do the job correctly.
Yes, you could dump oil in there, but if your opening things up, why not do it right, instead of doing it twice?
To add fluid/oil you need the tubes straight up and down, collapsed, and the oil needs to be measured from the top of the tube, to the surface of the oil etc.
If you use ONE measuring cup, and dump X amount of oil in one leg, then refill the cup, and do the other, you'll have different levels in each fork, as the fluid clings to the sides of the measuring cup.
You can get by that by using TWO measuring cups, at least that way, they will be even, and twenty minutes after you finish the job, you'll find about 1/2 inch of oil in each cup ;)
I personally would rather fix things correctly, while the bike is safe in the garage, rather than take short cuts, and can go south somewhere on the road.
A leaking fork seal can/may also take out your brake pads, and compromise the ability to use your brakes when needed.
Back under the bus I go....
:WCP1:
 
Joined
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At rest the fork oil level should be a certain distance from the top of the tube. I can't remember what that is at this time but probably pretty simple to perform. Obviously other Stoc members know just as much or more than I do. If you're losing oil out the bottom cartridge bolt of the fork housing ensure those are tight. Wipe it down and clean the surface with brake clean. If you're losing oil past the seal then perhaps there is dirt. Fashion yourself a seal cleaning tool. Clean the seal and wipe clean. Keep an eye on the forks in the mean time. Then as another member suggested rebuilding your forks over the winter. Good luck.
Dave
 
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If a minor leak, not enough to contaminate brake pads, you've lost very little. The oil level is still above the level of the seals. Clean out with a SealMate as best you can, the biggest cause of leaks is dirt accumulation. It will help for a while until you can rebuild the forks later.

It's a common practice to use less oil to provide more air cushion, especially with upgraded aftermarket springs. No worries on the little you have lost.

If you have a persistent leak, wrap a rag around the fork just below the seals and zip tie it on, check it frequently, if it's getting wet, time to get those forks off and rebuild them properly. I wouldn't worry about adding any oil at the moment.
 
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