FORKS! How to fill with oil and re-assemble?

[henerythe8th]

OK here's the back story.
I have a 2011 Stelvio. Had a fork oil leak on one leg. Didn't take care of it soon enough and didn't know how much oil that I may have leaked. Figured that I would pull them apart, replace seals, fill with fresh oil and move on.
To begin with I bought the wrong size seals. This 2011 has 45mm Marzocchi's on it. I didn't measure and thought that all 2011's had 50mm. Bought the seals in September from Synergy Seals.
I pulled the forks apart two weeks ago and discovered that the seals were the wrong size when I started to re-assemble after cleaning up and inspecting.
Could not source 45mm seals anywhere 'local' (in WA state) that I could find.
Contacted Rob @ Synergy seals because I didn't find 45mm wipers on his site. He told me to mail back the 50mm set and that he'd mail out a 45mm set! What a guy, no restock fee, no add'l shipping cost, etc.!!
Got the seals in the mail and pulled up the service manual that I downloaded.
All seems straightforward, all of the correct parts installed in the correct order on the cleaned up lower fork.
Fill with oil, according to the book, within 110mm of the top of the tube. Damn, sure seems to be taking a lot of oil...!
Look down and I've got a puddle of fork oil!
There's no way that the fork tube can be filled with oil within 110mm of the top of the tube, there's a hole bored in the tube below that level!

Re-examine the manual and the manual is showing a NON upside down fork tube where the measurement is being taken. Let the head scratching begin...
I cannot figure a logical way to do it the way it is shown in the manual.
I've searched the forum, the internet, looked at different versions of manuals (all the same) and am now asking the fine members of this forum:
Can anyone provide me with pertinent information?
Is there a how-to that I missed?

 

[canuck1969]

Are you filling it with the fork fully compressed. If it is not fully compressed it will come out of that hole. Also, when you pour fluid in, from the fully compressed sate, pump the fork up and down a few inches. This will make sure that the dampeners are full of oil. Once all the oil is in let it rest a few minutes so there is no air bubbles. I tap the sides of the fork with a rubber mallet a few times just to make sure. Then recheck the level and add if needed. The 110 will fit with no problem. Also, the 110 is without the spring and pre-load spacer.

 

[henerythe8th]

Are you filling it with the fork fully compressed. If it is not fully compressed it will come out of that hole. Also, when you pour fluid in, from the fully compressed sate, pump the fork up and down a few inches. This will make sure that the dampeners are full of oil. Once all the oil is in let it rest a few minutes so there is no air bubbles. I tap the sides of the fork with a rubber mallet a few times just to make sure. Then recheck the level and add if needed. The 110 will fit with no problem. Also, the 110 is without the spring and pre-load spacer.

View attachment 8402

Thanks!
I don't know how many times that I would have read the manual and still messed this up!
And thinking about it, doing it the way that I was trying to assemble the 'sleeve' in the 'stem' would have been impossible!
A tiny bit of discussion and a nights sleep (woke up a few times with it on my mind) and it makes way better sense!

Thanks again!

 

[Campagman]

Thinking my my 08 needs a fork service, never been touch in 30000 miles. One side has had a slight weep for several years so I guess I need some new seals.....but looking at the manual there are a number of special tools .....do I need anything that special or can the work be done with common tools, a vice etc.

 

[John Warner]

The 'special' tools are only needed if you want to dis-assemble the Damper and Spring assembly.
I left mine assembled, makes it a 30-min job.

Wind off all adjusters (Spring Preload and Damping) to minimum.
Loosen Fork Cap.
Remove fork(s).
Prise off Dust Cap.
Loosen Damper Rod Bolt (bottom of leg).
Remove Seal retaining Circlip.
Remove Fork Cap.
Pour out Fluid.
Remove Damper Rod Bolt.
Pull the Forks apart sharply, a few tugs should do it, it's like using a Slide-Hammer.



Should then look like the pic above.

Clean all the parts and reassemble with New Seal.

Fill with correct amount of your preferred Fluid, I used 10W.
Can't recall the exact amount now, around 600cc though.
Not sure of the capacity difference (if any) between the earlier 50mm Forks and the later 45s.

The 110mm measurement isn't critical, a few mm either way isn't going to make any difference when you have so much adjustment (Comp & Rebound) available.

 

[Campagman]

Cheers John, sounds straightforward....it will be done then I in the not too distant future.

I did buy some seals a long time ago, just need to find them!

 

[John Warner]

I did what Henerythe8th did, but the other way round.
Ordered the later 45mm seals before I realised there were two sizes.

 

[canuck1969]

Don't assume that your seals are worn.

Before you take them apart and the forks off the bike, clean the seals and see if they still leak. You can buy a seal cleaner for very cheap (like $5), or use a thin piece of plastic like from a blister package and wipe the seal clean. Do a search on how to clean them and you will find several good methods. 9 time out of 10 it is just some grit under the seal that is making it leak. As long as it has not gotten to the point that it has scored the seal you will be fine. As long as you clean them out every so often, a fork seal can last a very long time as long as it does not see abnormal abuse. Save yourself some time and money and clean it out first to see what happens. Then all you need to do is change the oil which requires no disassembly of the fork other than removing it from the bike.

Here is the one I have. I bought 4 of them to have in the shop and take on my bikes. I assume you can be Motion Pro in the UK.

http://www.amazon.com/Motion-Pro-Seal-Mate-Cleaner/dp/B0039LDF4A

 

[John Warner]

You may as well replace them if you have the Forks apart for a clean, check, and fresh Oil.
After 30,000 miles they'll be due for replacement, they do deteriorate eventually.

 

[canuck1969]

Not true ....seen bikes with well over 100,000KM and still have original functioning seals. As long as you keep them cleaned they could last a really long time. If they are weeping and you clean them and the weep goes away then your seals are in good conditions. You will know the difference between a worn seal and a dirty seal. One will have a gentle weep that barely makes it to the bottom of the fork, and the other will pour out all over your brakes discs.

What kills seals is inactivity for a long time and it dries out (not just winter storage, like a year or more) and grit on the faces.

Just my two cents...take it or leave it.

 

[Campagman]

Given that I've had a weep on the left side for 5 years and ridden properly off road, being buried in mud, through rivers etc then I think I'll go for new seals, £25 ish I think for seals and dust caps.

After that I'll get a seal cleaner.

I'm also going to get some clear helicopter bathe to protect the top stanchions, I've had some already in place but it's starting to lift, be easier to fit with the stanchions out of the clamps

 

[John Warner]

I'm not going to disagree with you Canuck, but it will depend a lot on their use/environment.
Yes, they can seemingly last forever, but those that have a 'hard' life (as campagman describes above) can wear or suffer damage, or even just deteriorate in storage as you mentioned.

Considering their low cost, I always replace them when rebuilding Forks.
It's the same for me with any Seals, Sump Plug, Caliper Banjos, Oil lines etc.

Maybe it's my background in Aircraft Engineering, we always replace Seals when they're disturbed/disassembled, it's just good practice.

 

[Campagman]

John,
where did you get you seals from, OEM or pattern? There seems a big variation in cost

 

[John Warner]

The first ones I got were from ebay, but were the wrong size.
They were Pyramid ones, came with 'Seal Buddy' tool and grease.
http://www.ebay.co.uk/itm/Fork-Seal...12-45x58x11-/390967886138?hash=item5b0780813a
I ordered them before I knew there were two different sizes (50mm Early and 45mm later Forks).

I got the correct set (50mm) from my local Bike Shop (PDQ Taplow) as I'd stripped the Forks down before I realised my error, and needed them pronto.
Paid £15, don't recall the make but they weren't cheap-and-nasty, Larry (at PDQ) doesn't stock c**p!

 

[Ray1150]

I've used this place for a long time, great prices and service, often offer a number of different quality offerings of the same product.
http://simplybearings.co.uk/shop/

 

[John Warner]

Me too.
I didn't realise they did 'proper' Fork Seals, most industrial suppliers only stock the single-lip shaft seals.

Thanks for the heads-up!

 

[sabre64]

Changing the oil to the forks will save seals, since the oil gets contaminated and stinky too

 

[Tomas Vecera]

Are you filling it with the fork fully compressed. If it is not fully compressed it will come out of that hole. Also, when you pour fluid in, from the fully compressed sate, pump the fork up and down a few inches. This will make sure that the dampeners are full of oil. Once all the oil is in let it rest a few minutes so there is no air bubbles. I tap the sides of the fork with a rubber mallet a few times just to make sure. Then recheck the level and add if needed. The 110 will fit with no problem. Also, the 110 is without the spring and pre-load spacer.

View attachment 8402

It is very important information for me, thanks, but I have one question please. 110mm is when fork fully compressed from rim of sleeve, but in this case stem sticking out of the sleeve 20 mm. Is it OK? The picture looks a little different than it really is. Thank you.

 

[Litch]

Just about to replace my fork seals (2014 45mm) as one is leaking again.
Previously both have been replaced at very low mileages by the servicing dealer and here we go again approaching annual service time and one is weeping again but rather than get them to do it I am going to replace them myself (and yes I know all about using a seal cleaner).
Reading John's guide, the only thing I would worry about is about disassembling the spring / damper assembly. If you don't do this then you can't measure the oil level as that has to be done with the spring not fitted, ok of you are certain of the amount of oil but if you are not (and I can't find the quantity listed anywhere) then measuring is the way to go and for that the spring has to be removed?

 

[Litch]

Replaced the seals on one leg only yesterday. I was going to do both but I am not happy with the fitment of the dust seal so am holding back until I can see how it works.
Stripping the fork was easy enough as was separating the spring from the damper assembly so measuring the oil is no big deal, I did try to measure the quantity of oil as I topped up and it appears to be around 630cc but I will check that when I do the other leg.
The reason I only did a single side is that the dust seal is not a good fit at all and I have some investigation to carry out. They are the same make as the ones already fitted by my dealer (NOK) but they appear to be slightly different and certainly don't fit as well.