Replaced leaking fork seal, leaks 4 weeks later.

[Blackshear]

Alright, so about 4 weeks ago I replaced a leaking fork seal, and holy shit the oil was disgusting. Almost liquid silver, but the seals didn't look so bad.
Anyhow, I cleaned it out and notice my tubes were bent, but nothing that anyone in the workshop was concerned about. (Dad, his childhood mate who does MX, and two other after-work stragglers).

I just noticed today, after wiping off what I thought was residual fork oil from the dust cap, but it came back again on the way home.

TL;DR
New fork seals, leaking again.
What should I do? Are the tubes bent enough that they'll suddenly leak 4 weeks later, or is this another problem entirely?

[Robert Taylor]

Alright, so about 4 weeks ago I replaced a leaking fork seal, and holy shit the oil was disgusting. Almost liquid silver, but the seals didn't look so bad.
Anyhow, I cleaned it out and notice my tubes were bent, but nothing that anyone in the workshop was concerned about. (Dad, his childhood mate who does MX, and two other after-work stragglers).

I just noticed today, after wiping off what I thought was residual fork oil from the dust cap, but it came back again on the way home.

TL;DR
New fork seals, leaking again.
What should I do? Are the tubes bent enough that they'll suddenly leak 4 weeks later, or is this another problem entirely?

Condition of fork bushings?

Condition of fork tubes i.e pit marks any other marks?

How did you actually instal them?

Brand of seals?

What is runout on the tubes?

Condition of dustcaps?

What do you do as a cleaning regime on the chrome sliders?

[F5 Dave]

Indeed, if the oil was full of silver particles that was likely from the bushes that are getting hell from the bent tube. As will the seals. Crappy seals leak quickly in less than perfect conditions. Also many seals are damaged from haphazard installation. Chrome on some bikes gets over polished (and this is where I'm into my opinion rather than the inside word of an expert); seals don't seem to want to seal well in this condition.

On 80s yams worn polished chrome seemed to respond to gently sandpapering in a hone pattern with a twin swirl twisting pattern, apparently an old hydraulic ram trick, maybe a wives tale but it did seem to do the trick. I would not suggest this on a low mileage serviceable fork, but I've done this to many of my old nails in the past where the chrome is mirror like & it has been successful.

[Blackflagged]

Just a suggestion ,you didn`t over fill them?Or yes reading more the bend.

[Blackshear]

Firstly, apologies for the lack of thanks and posting.


Condition of fork bushings?

Condition of fork tubes i.e pit marks any other marks?

How did you actually instal them?

Brand of seals?

What is runout on the tubes?

Condition of dustcaps?

What do you do as a cleaning regime on the chrome sliders?
Dunno what bushing are, didn't at the time.
Tube surfaces themselves were fine, rather polished as one would suspect.
Circlip removed, inserted seal, put a steel tube with a large enough diameter to slide down the fork without touching, and proceeded to gently and evenly deadblow that sucker in.
Brand of seals, I can't remember. They were red and came with stickers, if it helps.
Quick google taught me nothing as to what fork runout is. Sorry.
Dustcaps seem slightly perished/cracked at the top, though both a sales attendant and workmates didn't see a problem with them.
Cleaning regime? Lol.

I learn things as I go, and mostly try things myself. It's the only way I can retain a new skill.


Indeed, if the oil was full of silver particles that was likely from the bushes that are getting hell from the bent tube. As will the seals. Crappy seals leak quickly in less than perfect conditions. Also many seals are damaged from haphazard installation. Chrome on some bikes gets over polished (and this is where I'm into my opinion rather than the inside word of an expert); seals don't seem to want to seal well in this condition.

On 80s yams worn polished chrome seemed to respond to gently sandpapering in a hone pattern with a twin swirl twisting pattern, apparently an old hydraulic ram trick, maybe a wives tale but it did seem to do the trick. I would not suggest this on a low mileage serviceable fork, but I've done this to many of my old nails in the past where the chrome is mirror like & it has been successful.

Yeah, I've flicked off a few e-mails to people who may be able to help with a replacement tubes, so this will hopefully be sorted in the next two weeks if I don't die. Sandpapering is a nice trick. Further up my forks, there does seem to be a cross-sanded texture.


Just a suggestion ,you didn`t over fill them?Or yes reading more the bend.

Didn't overfill, but yes there is a bend in them. It's only about 2mm out from the other side, but I want them replaced, or at least un-bent.

Anyone know of a place around the shore (Or anywhere, for that matter) that can un-bend thin-walled pipes?

[Robert Taylor]

Firstly, apologies for the lack of thanks and posting.


Dunno what bushing are, didn't at the time.
Tube surfaces themselves were fine, rather polished as one would suspect.
Circlip removed, inserted seal, put a steel tube with a large enough diameter to slide down the fork without touching, and proceeded to gently and evenly deadblow that sucker in.
Brand of seals, I can't remember. They were red and came with stickers, if it helps.
Quick google taught me nothing as to what fork runout is. Sorry.
Dustcaps seem slightly perished/cracked at the top, though both a sales attendant and workmates didn't see a problem with them.
Cleaning regime? Lol.

I learn things as I go, and mostly try things myself. It's the only way I can retain a new skill.



Yeah, I've flicked off a few e-mails to people who may be able to help with a replacement tubes, so this will hopefully be sorted in the next two weeks if I don't die. Sandpapering is a nice trick. Further up my forks, there does seem to be a cross-sanded texture.



Didn't overfill, but yes there is a bend in them. It's only about 2mm out from the other side, but I want them replaced, or at least un-bent.

Anyone know of a place around the shore (Or anywhere, for that matter) that can un-bend thin-walled pipes?

Your installing regime is a good part of the problem. Only a proper and properly sized seal driver will ensure an even and concentric pressure on that seal as you drive it in. The internal steel casings in fork seals are quite thin and its therefore very easy to distort the seal on installation. It also helps to significantly warm the top of the fork tube with a heat gun and lubricate the outside edge of the seal. That will dramatically reduce the amount of installing pressure required.
I also have a HUGE issue with those red seals on the market. We flat refuse to instal them as we have seen a lot leak including many proffessionally and carefully installed. They also create an enormous amount of friction ( dont believe the marketing lies ) Friction is one of the biggest enemies of great suspension action

[Blackshear]

Your installing regime is a good part of the problem. Only a proper and properly sized seal driver will ensure an even and concentric pressure on that seal as you drive it in. The internal steel casings in fork seals are quite thin and its therefore very easy to distort the seal on installation. It also helps to significantly warm the top of the fork tube with a heat gun and lubricate the outside edge of the seal. That will dramatically reduce the amount of installing pressure required.
I also have a HUGE issue with those red seals on the market. We flat refuse to instal them as we have seen a lot leak including many proffessionally and carefully installed. They also create an enormous amount of friction ( dont believe the marketing lies ) Friction is one of the biggest enemies of great suspension action

So I guess it's off to the bike store for a proper installation in the next two weeks.
I didn't warm the tube, but I did run some oil around the inside and outside of the seal before my apparently extreme method of installation occurred.
I will agree with the friction. Though I did put in a heavier weight oil, and though they were new, there was a questionable amount of effort required to get some movement in them.

Cheers for the input, I might not be buying a new phone on my birthday after all.
HTC HD2, drooooooool.
Both tyres, a chain and now fork issues aren't a great time to be collaborating for my WOF.