Fork seal fitting

A straightforward job. Which can be done in as little time as 10 minutes. No cycle parts i.e. tank etc, need be removed

The tools needed .



Start by removing the small plastic cap on the top of the fork leg.



The nut underneth can be corroded, so use a hex socket and not a bi-hex if you can



Hex socket.



Place a 22mm spanner on the flats at the top of the leg , under the top yolk.
And the 14mm socket onto the top nut. And undo the top nut.





With the nut removed, push the fork slider down and out of the top yolk.
The front end will be all sloppy, allowing you to push the bars around and out of the way, and the front wheel can be moved in any direction for conveniance.

Pull the fork slider up and out of the stanchion. Wipe the leg as it's removed, as it will have oil residue on it.





Prise out the dust cover - These can be split and deformed, so look before doing the job and have a new one ready if needed.



Underneth you'll see the seal circlip. Prise free with a small screwdriver.



With a seal puller, or similar instrument, pullout the old seal. This is easiest done with my puller by pushing the fork leg as far forward as you can . Remember, the front wheel can moved to almost any position.







There is a washer under the seal. Pick it out,and clean it - Again, this can be corroded.






New seal - Top



New seal - underneth



Locate the new seal in place with your fingers, you can push it home a fair way to start it off



Then with a correct sized socket ( i use a 1" 3/8ths) you want it to run around the outside of the seal, but be small enough to fit inside the slider lips. Fit an extension bar onto the socket, and tap home the new seal.





Refit the circlip .


Refit the dust seal, just a push fit.



Then with a 3mm allen key, undo the small air bleed bolt on top of the fork stanchion and remove it.



making sure you don't lose or damage the "o" ring on the bolt



Push the stanchion carefully back into the slider -remember the front wheel forks can moved around for the best position



Then pull the stanchion back up, so it's in line with the top yolk, in the same position where it will be when it's in place - Now keep the stanchion in place, and replace the air vleed screw.



Now position the fork stanchion back in place in the top yolk, and refit the nut.



Hold the stanchion with the 22mm spanner and do up the 14mm nut, replace the top yolk plastic cover. Job done.

Thanks for the demo Neil. I've got a leaky one on my 1100GS and will now give it a go!

Neil

Neil "Haynes" Harrison does it again.

In hindsight calling him Haynes is probably an insult

Just made me go out to the garage & pop the plastic caps off to see if they were corroded, They weren't, & won't now that I've brushed ACF 50 on them

Outstanding write-up and pictures! Certainly a much easier job than changing the seals on my Mille's forks last year!!.

<BR>Top shelf Neil

- Jim<BR><BR>

fork seal replacement

Mr Steptoe, Sir
Ever thought of writing a manual?
It would be a best seller amongst GS owners I am sure.
Keep them coming
:cool

Is there not some oil to go back in? If the seal was leaking, the oil level must have dropped.
Probably the only way to check the level is to drain all the oil and re-fill.

atkigasser said:

Is there not some oil to go back in? If the seal was leaking, the oil level must have dropped.
Probably the only way to check the level is to drain all the oil and re-fill.

Click to expand...

As i said at the beginning of the thread - My seal wasn't leaking, but i changed it to show how easy it is.

Unless you'd left the seal leaking for months, and have your brake calipers and wheels covered in oil, you won't need to add any oil.
They aren't like conventional forks where the oil acts as damping fluid. There isn't any valves or damping rods etc in the legs. It's basically just to lube the stanchions in the sliders and stop them from seizing/wearing.

You may think you've lost a lot of oil if you find a seal leaking. But a tiny bit of oil goes a long long way.
If your anal over it, measure where the level is from the top of the non leaking slider, and compere it with the leaking side.

Oil quantity per leg is 485 cc

Steptoe, just about to do mine this weekend so this ideal. Must be something to do with riding throughtout the winter months. What did you use to lubricate the new seals proir to fitting, from the picture it looks like a grease of some kind or is it vasaline?

Good post, thanks. Ps you don't make it clear that you replaced the seal washer. Or did I miss it. I'm only an old nitpicker

suffolk pig said:

. What did you use to lubricate the new seals proir to fitting, from the picture it looks like a grease of some kind or is it vasaline?

Click to expand...

They do have a grease on the surface, but i use Marine Grease, especially in/under the dust covers .

harry said:

. Ps you don't make it clear that you replaced the seal washer.

Click to expand...

I cleaned up and re-used the old washer.

Had to change mine last night, 20 minutes and €12.

Steptoe, brilliant post, proved very handy and reassuring before I started.
I did as you said with the first fork leg, but with the second the the Slider
just slipped off the Tube, replaced the seal and oil (milky coloured) and slid
it back on without taking off the tube.

Brilliantly simple, took me about 20 minutes, thanks muchly Steptoe.



BTW, my seals went very suddenly on both sides, they both looked okay but
while they were out.

thanks Steptoe, thats 20 minutes on Saturday sorted time for the rest of the day.

What a helpful thread.

Changed a leaking seal tonight in 20 minutes thanks to this post.

Thanks Neil.

thanks for a great how to!

for those of you stuck in the middle of nowhere: the size is 35x48x11 mm

Hi all,

I am going to change both my seals on my 1100 RT. Only one is leaking, but I will change them both.

That means that I will also change the fluid inside. Now... What I do not understand is this... After I put the fluid in the tubes, undo the small air bleeder on the top of the stanchion, how do I know when do I close it?

I mean, is there suppose to be some air in the tubes besides oil?

I will replace this tomorrow evening and would really appreciate an advice until then

Dan.

If you have a stubborn seal that won't budge, warm the fork leg around the seal with a heat gun or similar -worked a treat on my K1.

fork seals for a gsa

Hi can some one tell me the size of the fork seals on a 02 gsa.Thanks Phatphunker

Hi, great posting thank you. One thing that seems strange is that the seal has the spring facing away from the oil, these normally fit the other way round, anyone know why BMW has it this way?

I think you will find that there is a spring on both sides of the seal, therefore doubling the efficiency and also a double edge both sides. Changed both mine a few weaks ago, wish I'd spotted this first but then again I cleaned out the lower legs and put in new oil anyway.