Removing very corroded fork seal

Need advice on which oil to use or which tyre best suits you? Share your topic and get help here.
Post Reply
User avatar
RodneyT
Posts: 38
Joined: Mon Aug 30, 2021 2:53 am

Removing very corroded fork seal

Post by RodneyT »

Hi All
Hoping someone may have some tips for removing a fork seal from a '97 VTR. The bike hadn't been used for many years and I'm slowly working over it to make it into another track bike.
The fork dust seals had completely perished and the metal bits of the seals themselves are badly corroded. There was so much rust and corrosion that I couldn't see the fork seal retaining clip at first but managed to find and remove them from both forks. I managed to get one out after a helluva lot of heaving on the fork stanchion with both hands and the bottom of the fork leg clamped in a vice with the axle butting up against the vice to prevent it from slipping out of the jaws.
However, the same treatment for the second leg has so far yielded no result. I flooded the top of the seal with WD40 and left it for a couple of days, gently heated the top of the fork leg and still no movement of the old seal. The fork stanchion is now starting to bind on something inside and thinking maybe I'm deforming the bushes with all the force I've been putting them under to try and move the seal.
Here's a photo of the seal that I managed to get out:
Image
and here's the one that is still stuck:
Image

Any ideas anyone?
User avatar
MacV2
Posts: 17543
Joined: Sun Jan 21, 2007 12:07 pm
Location: Grain

Re: Removing very corroded fork seal

Post by MacV2 »

If you have a spare lower then just cut it... Cutting disc in a grinder cut through the the top of the lower across at an angle.

If not you could try drilling into the seal multiple little holes it might release the pressure.

Failing that keep going on the heat slide hammer treatment... It will give in the end.

The jamming is probably the lower bush has moved & is causing it to bind.

Good to see the safety flip flops in use... ! 8O
Making up since 2007, sometimes it's true...Honest...
User avatar
MacV2
Posts: 17543
Joined: Sun Jan 21, 2007 12:07 pm
Location: Grain

Re: Removing very corroded fork seal

Post by MacV2 »

Would have to check but I might have a spare lower if you need one.
Making up since 2007, sometimes it's true...Honest...
User avatar
sirch345
Site Admin
Posts: 21856
Joined: Mon Aug 25, 2003 10:35 pm
Location: The West Country.

Re: Removing very corroded fork seal

Post by sirch345 »

There is possibly another way, but it may depend on what equipment you have in your garage/workshop. Have a read in this link:
viewtopic.php?t=39789&start=15

Chris.
User avatar
RodneyT
Posts: 38
Joined: Mon Aug 30, 2021 2:53 am

Re: Removing very corroded fork seal

Post by RodneyT »

Thanks for the info, guys
I'll try digging out what I can of the seal and get some more penetrating oil in there and leave it a bit longer. If I can manage to get out most of the rubber part of the seal it will hopefully have less holding it in there.
I don't have a spare fork leg or a press but I have found a wrecker here in Australia who specialises in VTRs so will investigate getting a fork lower as well
Oh, and that's the old safety 'boots'. You'll be glad to know I have a new pair :D
User avatar
sirch345
Site Admin
Posts: 21856
Joined: Mon Aug 25, 2003 10:35 pm
Location: The West Country.

Re: Removing very corroded fork seal

Post by sirch345 »

RodneyT wrote: Mon Jun 10, 2024 12:11 am Thanks for the info, guys
I'll try digging out what I can of the seal and get some more penetrating oil in there and leave it a bit longer. If I can manage to get out most of the rubber part of the seal it will hopefully have less holding it in there.
I don't have a spare fork leg or a press but I have found a wrecker here in Australia who specialises in VTRs so will investigate getting a fork lower as well
Oh, and that's the old safety 'boots'. You'll be glad to know I have a new pair :D
I find 'Plus Gas' works better than 'WD40'.

Good luck with it, I think you're going to need it :wink:

Chris.
MK_WF
Posts: 140
Joined: Mon Aug 31, 2015 6:02 pm
Location: Wolfenbuettel/Germany
Contact:

Re: Removing very corroded fork seal

Post by MK_WF »

As an addition to the method to fill the complete volume with oil and put it on a press:

I managed to do this without a press using an inertia effect.
You fill up with oil and screw on the upper cap.
Then put something "hard enough but soft enough" on the ground like a thick piece of wood (better use softer sorts than hardwood).
Hold the complete fork stanchion in a similar position like it's in the bike and ram it into that wood like you'd pinch a spear into the ground.
The effect is that the aluminum is stopped (but not damaged) and the steel parts inertia still drives it downwards. This results in a pressure peak in the oil and if the seal is not secured, it's starting to move upwards until oil can escape.

Yes, this is a violent method and it takes a couple of hits, but in my cases it was driving out the seal halfway until it leaks - the rest was carefully done with a screwdriver.
Bye
Martin
neil
Posts: 378
Joined: Fri Mar 10, 2006 9:52 pm
Location: E. Yorkshire

Re: Removing very corroded fork seal

Post by neil »

I had one fork leg that would not come apart no matter what I tried. I carefully drilled through the fork seal at an angle so then I could get a small screwdriver in to prise the old seal out. It worked for me but be careful not to mark chrome on fork leg if you try it.
redvtr
MK_WF
Posts: 140
Joined: Mon Aug 31, 2015 6:02 pm
Location: Wolfenbuettel/Germany
Contact:

Re: Removing very corroded fork seal

Post by MK_WF »

neil wrote: Tue Jun 11, 2024 2:11 pm I had one fork leg that would not come apart no matter what I tried. I carefully drilled through the fork seal at an angle so then I could get a small screwdriver in to prise the old seal out. It worked for me but be careful not to mark chrome on fork leg if you try it.
As a variant of this equally gruesome method, you could turn in one or two wood screw(s). It uses the bore as a thread and as soon as it reaches the lower seat surface, turning creates a force on the seal in the upward direction.
Looks like this after successful removal
Image
Bye
Martin
MK_WF
Posts: 140
Joined: Mon Aug 31, 2015 6:02 pm
Location: Wolfenbuettel/Germany
Contact:

Re: Removing very corroded fork seal

Post by MK_WF »

Aaaand as we already discuss botching things up properly:

If you want a proper rebuild, you're gonna disassemble the stanchion anyway.
So why not loosen the screw at the bottom and pull out the upper stanchion from the lower leg through the seal. It's damaged anyway, so there's nothing to loose.
Similar to my other method it requires a bit of brute force to pull it out. Shove it in fully and then give it a bit of a speedy pull-out.

But with the upper leg out, there's no chrome to damage and you could use a tyre iron or a screwdriver to get under the seal and pry it out.
Bye
Martin
integerspin
Posts: 40
Joined: Sun Jan 15, 2023 2:55 am
Location: Reigate

Re: Removing very corroded fork seal

Post by integerspin »

Acid remove the rust?
tony.mon
Posts: 16022
Joined: Wed Jul 25, 2007 10:46 pm
Location: Norf Kent

Re: Removing very corroded fork seal

Post by tony.mon »

integerspin wrote: Wed Jun 12, 2024 7:30 pm Acid remove the rust?
Acid or anything corrosive would eat the aluminium alloy a lot more than the rusty steel.
It's not falling off, it's an upgrade opportunity.
integerspin
Posts: 40
Joined: Sun Jan 15, 2023 2:55 am
Location: Reigate

Re: Removing very corroded fork seal

Post by integerspin »

tony.mon wrote: Wed Jun 12, 2024 8:54 pm
integerspin wrote: Wed Jun 12, 2024 7:30 pm Acid remove the rust?
Acid or anything corrosive would eat the aluminium alloy a lot more than the rusty steel.
Not necessarily.
I remove broken bolts or taps from aluminium with battery acid and a battery charger, basically i am anodising the aluminium and the lump of steel gets eaten. No damage to the ali.

Then there is always alum. I was always told Alum removes broken taps from aluminium, but never had any success myself.

However that is last resort as it's so much quicker to remove mechanically.
tony.mon
Posts: 16022
Joined: Wed Jul 25, 2007 10:46 pm
Location: Norf Kent

Re: Removing very corroded fork seal

Post by tony.mon »

integerspin wrote: Thu Jun 13, 2024 2:31 pm
tony.mon wrote: Wed Jun 12, 2024 8:54 pm
integerspin wrote: Wed Jun 12, 2024 7:30 pm Acid remove the rust?
Acid or anything corrosive would eat the aluminium alloy a lot more than the rusty steel.
Not necessarily.
I remove broken bolts or taps from aluminium with battery acid and a battery charger, basically i am anodising the aluminium and the lump of steel gets eaten. No damage to the ali.

Then there is always alum. I was always told Alum removes broken taps from aluminium, but never had any success myself.

However that is last resort as it's so much quicker to remove mechanically.
Interesting. I hadn't considered an electrolytic solution.
It's not falling off, it's an upgrade opportunity.
User avatar
sirch345
Site Admin
Posts: 21856
Joined: Mon Aug 25, 2003 10:35 pm
Location: The West Country.

Re: Removing very corroded fork seal

Post by sirch345 »

tony.mon wrote: Thu Jun 13, 2024 9:33 pm
integerspin wrote: Thu Jun 13, 2024 2:31 pm
tony.mon wrote: Wed Jun 12, 2024 8:54 pm
Acid or anything corrosive would eat the aluminium alloy a lot more than the rusty steel.
Not necessarily.
I remove broken bolts or taps from aluminium with battery acid and a battery charger, basically i am anodising the aluminium and the lump of steel gets eaten. No damage to the ali.

Then there is always alum. I was always told Alum removes broken taps from aluminium, but never had any success myself.

However that is last resort as it's so much quicker to remove mechanically.
Interesting. I hadn't considered an electrolytic solution.
I thought the same as Tony :thumbup:

Chris.
Post Reply