Leaking now not leaking fork seals

[BBB]

Can fork seals reseal themselves? I'm thinking not...

When on the bike and compressing the forks there was a definite oily line and smeary tide mark above both dust seals. Bike lives outside.

Taken the forks off and ordered seals and bushings. Brought the forks inside to start stripping as they've been sat in the shed. No oil at all on the stanchions, lots of compressing, inverting and general messing and nothing. Oil in forks as I can hear it gurgle but both forks clean as a whistle. I don't want to strip and replace if not necessary but I don't want to put the bike back together only for them to leak.

Is it common for them not to leak once off the bike and not supporting the weight?

[Skub]

If a bike has been sat for a few weeks,fork seals can shrink and cause an oil line,but usually this sorts itself out when the bike is used regularly.

My ZX10R used to do it every Spring,but a decent ride and it was fine.

[KungFooBob]

Sometimes it's grit between the seal and the stanchion that causes the leak, you can clean it out with feeler gauges or thin plastic, no reason why it might not work it's own way out.

Or maybe all the oil has already leaked out

[Yorick]

Weigh them to see if one has lost oil.

[BBB]

If a bike has been sat for a few weeks,fork seals can shrink and cause an oil line,but usually this sorts itself out when the bike is used regularly.

My ZX10R used to do it every Spring,but a decent ride and it was fine.

Sounds like mine has done this (zx6r) I may have wasted £60 on seals. Tempted to change the oil now they're off just to prove a point.

Will weigh them too, need to find some scales.

[wull]

I think the difference would be negligible. Leaking forks always seem worse than they really are and if yours was a weep then you’ll never tell the difference.

I had a bad leak last year after a track day, ran it for a further two weeks because I had to and it was quite bad when I got round to it.

I wanted to see how much I had lost and emptied both forks and measured the amount that was left and the difference between the two was very minimal, negligible at best.

[Hairybiker84]

Weigh them to see if one has lost oil.

Would only work if the forks are identical, lots aren't!

[Yorick]

Weigh them to see if one has lost oil.

Would only work if the forks are identical, lots aren't!

I know, but it could be a starting point.

[the_priest]

Fresh fork oil is a good idea if you don't know when they were last done. It does make sense to give them a refresh if you have them stripped off already anyhow.

[Tricky]

If a bike has been sat for a few weeks,fork seals can shrink and cause an oil line,but usually this sorts itself out when the bike is used regularly.

My ZX10R used to do it every Spring,but a decent ride and it was fine.

Sometimes it's grit between the seal and the stanchion that causes the leak, you can clean it out with feeler gauges or thin plastic, no reason why it might not work it's own way out.

Or maybe all the oil has already leaked out

Very much so- both above are common and I've lost count the number of times I've fixed a fork oil leak on my off-roader by sliding a thin bit of plastic around the seal - I have one of these which is specifically designed for the purpose but as Bob says, a piece of thin plastic/cable-tie or feeler gauges will usually do the same job



And I agree with priest- if they're out, I'd at least change the oil anyway, even if you decide to not swap the seals at this time
,

[The Spin Doctor]

Parked my bike up before a trip to NZ a couple of years ago, it had just been cleaned and waxed, then stored under cover...

Came back six weeks later, took the cover off and there was oil all down one leg and over the brake / caliper.

Since the forks were clean as a whistle before I parked it with not the slightest hint of a leak, I can only assume it was fluctuations in temperature changing air pressure in the fork itself. It was about -5 at night when I left, and about 18 c in the day when I got back.

I did buy a Seal Mate to see if there was any grit - but after a good clean up / ride, it sorted itself out... that was three years ago! Never did use it.

[BBB]

As they are sat in my kitchen I'm going to change the oil but not the seals and bushes as its a bit unnecessary. Got some touch up paint for the more noticeable chips and scratches too.

[BBB]

One leg looked as you'd expect, silvery black oil the other leg was more chocolatey in colour with a bit of rust on the springs and washers. Both got a thorough rinse with brake cleaner until clear and flushed a few times with fresh fork oil. Hopefully it'll be noticeable when riding.