Fork seal and oil change.

David Offor

Registered
I finally got round to doing my leaking fork seal.
I’m guessing that this has been covered before but maybe my post could offer something new.
After watching a couple of YouTube videos, I decided that it was definitely doable but I did have to make a tool, to be able to hold the tube down, against the spring, to get to the locknut (see photos).


1. Remove forks.

2. Slacken off top nut, 30mm socket/spanner, it won’t be very tight.

3. Tip fork upside down and empty out old fluid into a measure container (Optional, as the new level, is measured at 98mm, after refilling, with new fluid).

4. Now using a tool, to force down the tube against the spring tension, slide in an appropriately gapped piece of metal, under the lock nut.

5.Using the 30mm socket/spanner and a 17mm spanner, crack off the locknut and then unscrew the 30mm piece, remove the thin rod and now remove the clamping tool and gapped piece of metal, remove spring and lay parts on a clean surface, in order of disassembly.
6. Upend the fork and empty out any remaining fluid, by sliding the internal plunger in and out.
Slide tube off of the stanchion.

7. Remove dust cover, remove seal retaining clip, remove old seal.

8. Fit new seal, clip and dust cover (I used one of the old seals, as a spacer, to knock in the new one, also, make sure new seal goes back in the same way, as the old one came out, otherwise it will leak).

9. Carefully slide stanchion into tube (a YouTube video showed someone using some thin plastic wrapped around the end of the stanchion and then sliding the tube on).

10. Slide tube all the way down the stanchion and add new oil the book says about 480ml (but that is quite a bit over, when measuring the 98mm), pump the internal slider up and down a few times, to expel any air, now, using a steel ruler, measure from the oil level, to the top of the tube, add or subtract oil, until the measurement is 98mm.

11. Add spring, tube, thin rod.

12. I found that by unscrewing the locknut, up the thread a bit, it was easier to push down the tube, with the special tool and get the gapped piece of metal under the locknut, once the spring is compressed, wind the locknut down and measure 11mm of thread showing.

13. Screw top 30mm piece back on and tighten against the locknut (doesn’t have to be really tight).

14. Remove tool and gapped piece from under the locknut, slide up external tube and screw back onto the top 30mm section.

15. Repeat on other fork.

16. Fit forks.

17. Fit wheel.

18. Ride bike.

19. Try not to crash :thumbsup:

The tool I made worked a treat but took some time and I was lucky enough to have the correct materials, I’ve shown measurements in the photos and from what I saw in my Haynes Manual, there are other styles of tool, that will do the job or just borrow the proper one from someone.

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I finally got round to doing my leaking fork seal.
I’m guessing that this has been covered before but maybe my post could offer something new.
After watching a couple of YouTube videos, I decided that it was definitely doable but I did have to make a tool, to be able to hold the tube down, against the spring, to get to the locknut (see photos).


1. Remove forks.

2. Slacken off top nut, 30mm socket/spanner, it won’t be very tight.

3. Tip fork upside down and empty out old fluid into a measure container (Optional, as the new level, is measured at 98mm, after refilling, with new fluid).

4. Now using a tool, to force down the tube against the spring tension, slide in an appropriately gapped piece of metal, under the lock nut.

5.Using the 30mm socket/spanner and a 17mm spanner, crack off the locknut and then unscrew the 30mm piece, remove the thin rod and now remove the clamping tool and gapped piece of metal, remove spring and lay parts on a clean surface, in order of disassembly.
6. Upend the fork and empty out any remaining fluid, by sliding the internal plunger in and out.
Slide tube off of the stanchion.

7. Remove dust cover, remove seal retaining clip, remove old seal.

8. Fit new seal, clip and dust cover (I used one of the old seals, as a spacer, to knock in the new one, also, make sure new seal goes back in the same way, as the old one came out, otherwise it will leak).

9. Carefully slide stanchion into tube (a YouTube video showed someone using some thin plastic wrapped around the end of the stanchion and then sliding the tube on).

10. Slide tube all the way down the stanchion and add new oil the book says about 480ml (but that is quite a bit over, when measuring the 98mm), pump the internal slider up and down a few times, to expel any air, now, using a steel ruler, measure from the oil level, to the top of the tube, add or subtract oil, until the measurement is 98mm.

11. Add spring, tube, thin rod.

12. I found that by unscrewing the locknut, up the thread a bit, it was easier to push down the tube, with the special tool and get the gapped piece of metal under the locknut, once the spring is compressed, wind the locknut down and measure 11mm of thread showing.

13. Screw top 30mm piece back on and tighten against the locknut (doesn’t have to be really tight).

14. Remove tool and gapped piece from under the locknut, slide up external tube and screw back onto the top 30mm section.

15. Repeat on other fork.

16. Fit forks.

17. Fit wheel.

18. Ride bike.

19. Try not to crash :thumbsup:

The tool I made worked a treat but took some time and I was lucky enough to have the correct materials, I’ve shown measurements in the photos and from what I saw in my Haynes Manual, there are other styles of tool, that will do the job or just borrow the proper one from someone.

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Great step by step write up. Yes the 480ml of oil is over kill, 465 is a better starting point that is mentioned only here and there. These forks also did not come apart like the other inverted forks on the You Tube videos. The bottom of them just slide out & can't be used to slide hammer the old seals out. There is a special tool to pull them out I just used an exhaust spring puller since I had no care about the old seals. Also you need a special tool to hold the internals in order to remove the bottom allen bolt since I wasn't willing to try the impact gun since the take down order was way off from what I thought & did not want to risk having a problem.
 
Brilliant write up David, so many pics! Must have taken ages to upload them all lol.
By the look of your hands, I'd say you are a mechanic by trade!!
Your finger cracks with ingrained grease, dirt and oil, look just like mine!! :firing:
 
Great step by step write up. Yes the 480ml of oil is over kill, 465 is a better starting point that is mentioned only here and there. These forks also did not come apart like the other inverted forks on the You Tube videos. The bottom of them just slide out & can't be used to slide hammer the old seals out. There is a special tool to pull them out I just used an exhaust spring puller since I had no care about the old seals. Also you need a special tool to hold the internals in order to remove the bottom allen bolt since I wasn't willing to try the impact gun since the take down order was way off from what I thought & did not want to risk having a problem.
Hi Nastee.
Yep, i remember doing a set, that i had to do the ‘slide hammer’ technique with but i was happy to find, that it wasn’t needed with these, i didnt want to disturb the damper, so, there was no need to remove the Allen bolt, at the bottom of the fork, I’d only do that if a component inside, needed replacing.
After doing the first fork te second was pretty straightforward but without the tool, to pull down against the spring, it would’ve been a pain in the neck.
 
Hi Nastee.
Yep, i remember doing a set, that i had to do the ‘slide hammer’ technique with but i was happy to find, that it wasn’t needed with these, i didnt want to disturb the damper, so, there was no need to remove the Allen bolt, at the bottom of the fork, I’d only do that if a component inside, needed replacing.
After doing the first fork te second was pretty straightforward but without the tool, to pull down against the spring, it would’ve been a pain in the neck.
Yeah, I also made my own tool using a piece of exhaust tubing and welded nuts on it with bolts ground to a tapered end, and some solid rod welded to each side as handles to push down on.
I like making tools, very satisfying.
I did like your tool, very heavy duty!
 
Brilliant write up David, so many pics! Must have taken ages to upload them all lol.
By the look of your hands, I'd say you are a mechanic by trade!!
Your finger cracks with ingrained grease, dirt and oil, look just like mine!! :firing:
Thanks Kiwi Rider.
The photos uploaded pretty fast, where in nz are you? I’ve been there a few times, amazing place but I preferred the South Island.
Yep, I’ve been a mechanic for over 30 years now, not a fitter, fixed a lot of things broke a lot of things and broke and fixed a lot of things, that no one even knew about lol.
I found a way of getting all the ingrained oil out of my fingers, about 3 years ago.
Dishwasher tablet, break one in half, run a bowl of water, with hot Ish water in it, wet the hands and then scrub the tablet into the fingers and hands, crush the tablet and massage it into the hands, then comes the burning bit, put your hands in the water and hold them there the result is brand new hands.
I went through life, trying to cut the oil out, grind it out, used thinners, petrol, anything I could think of, nothing was effective but the dishwashing tablet method works perfectly.
 
No comments on how he lifted the front end? That’s thinking outside the box. I’m gonna have to steal that idea. I remove the rear wheel and tie the wheelless rear axle to my lift but that looks so much simpler.
 
No comments on how he lifted the front end? That’s thinking outside the box. I’m gonna have to steal that idea. I remove the rear wheel and tie the wheelless rear axle to my lift but that looks so much simpler.
It made sense to do it that way, i always work alone, so I’ve become used to thinking of different ways of getting over problems :thumbsup:

Note-: This method of lifting the front wheel only works with something above the bike (disclaimer). :D
 
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Thanks Kiwi Rider.
The photos uploaded pretty fast, where in nz are you? I’ve been there a few times, amazing place but I preferred the South Island.
Yep, I’ve been a mechanic for over 30 years now, not a fitter, fixed a lot of things broke a lot of things and broke and fixed a lot of things, that no one even knew about lol.
I found a way of getting all the ingrained oil out of my fingers, about 3 years ago.
Dishwasher tablet, break one in half, run a bowl of water, with hot Ish water in it, wet the hands and then scrub the tablet into the fingers and hands, crush the tablet and massage it into the hands, then comes the burning bit, put your hands in the water and hold them there the result is brand new hands.
I went through life, trying to cut the oil out, grind it out, used thinners, petrol, anything I could think of, nothing was effective but the dishwashing tablet method works perfectly.
Here's my effort at tool making . . . looks flimsy next to your's, but it does the job ok!
1599119


and here's my hand, notice any similarities lol?
I'll have to try that trick with the dishwasher tablet . .
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I have also been a working mechanic for over 30 years, we have a fair bit in common, worked on Subaru's for 20 years and then a country garage for 7 years, now I'm at the local Suzuki BMW m/cycle franchise working on bikes, great way to finish up my career as a mechanic!
I'm in the South Island, 30 miles west of Christchurch but commute to the city every day to work.
Did you visit ChCh when you were here? When were you over here? There's a lot of Brits here now, fled from the UK, they all say the same thing . . old Brittania just ain't what it used to be!
NZ is a greayt country, isolated from the trouble spots, but 1st world all the way, cost of living is high but that discourages the riff-raff, know wat I mean Guv'nor? lmao.
 
Yeah, I also made my own tool using a piece of exhaust tubing and welded nuts on it with bolts ground to a tapered end, and some solid rod welded to each side as handles to push down on.
I like making tools, very satisfying.
I did like your tool, very heavy duty!
I actually copied my one from a YouTube video, i was lucky that i had the ‘main’ piece, just needed to drill, tap a couple of 10mm holes (first 2 didnt lineup lol) and i had to turn out, part of a shoulder, on the lathe, cut it in half and wola, looked in the Haynes manual after I had made it, for tech info, then saw the home made one, in the photos doh!
Yes, it is satisfying making tools, speaking from my experience of places I’ve worked, improvising and working out problems, is becoming a thing of the past for most, everything is either buy new, throw away or give up, not good.
I think nz is still a place of fix and repair, i worked. A few times in a smal town called methven, in the South Island, for a guy called don smith, real old school, a great guy, part mauri.
 
Here's my effort at tool making . . . looks flimsy next to your's, but it does the job ok!
View attachment 1599119

and here's my hand, notice any similarities lol?
I'll have to try that trick with the dishwasher tablet . .
View attachment 1599120

I have also been a working mechanic for over 30 years, we have a fair bit in common, worked on Subaru's for 20 years and then a country garage for 7 years, now I'm at the local Suzuki BMW m/cycle franchise working on bikes, great way to finish up my career as a mechanic!
I'm in the South Island, 30 miles west of Christchurch but commute to the city every day to work.
Did you visit ChCh when you were here? When were you over here? There's a lot of Brits here now, fled from the UK, they all say the same thing . . old Brittania just ain't what it used to be!
NZ is a greayt country, isolated from the trouble spots, but 1st world all the way, cost of living is high but that discourages the riff-raff, know wat I mean Guv'nor? lmao.
Blimey, i need to up my game, yours looks a lot more professional than mine, painted too!
Photos are the best, great idea, to get the clearance around the 30mm top part, effective and a lot easier to make than mine.
Are you near Ashvegas, tniwald?
I was first in nz in 2005, for 3 months, after oz, on a 10 month backpack around the world, been there 6 times now.
Yep the uk now officially sucks, protectyour borders and keep your prices high, keep out the (mainly() useless English :lol:, luckily they still let me in.
 
Hi Nastee.
Yep, i remember doing a set, that i had to do the ‘slide hammer’ technique with but i was happy to find, that it wasn’t needed with these, i didnt want to disturb the damper, so, there was no need to remove the Allen bolt, at the bottom of the fork, I’d only do that if a component inside, needed replacing.
After doing the first fork te second was pretty straightforward but without the tool, to pull down against the spring, it would’ve been a pain in the neck.
Motion pro makes dampening rod removal tool $27 but is an in to short to work. Racetech has a longer one on Amazon $57. So cut tool in half inserted 3/4 x 3" plumbing pipe after grinding threads down then hammering down into place; weld & paint.

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Sorry I send the same pictures several times:banghead:

I compress the spring with ratchet straps. There is no need of anyone or holding plate with the notch.
Oil suzukui L01 = 2.5W but I put 5W
To have the good level i Use this smart tool:
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I tried to clamp aluminum tube in soft vise & turn bottom of dampner with wrench. Kept turning pipe though; found you can clamp tool in vise insert dampner in to tool turn bottom wich is a single part & top unscrewed. Internals accessed for valve, shim or spring upgrade. Maybe this will help others.

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