How to change a fork seal on an 1150

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Welsh

Grumpy Mutt
Joined
Jan 27, 2006
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Location
Jo,burg
Bike
BMW R1150GS
So as I mentioned, I popped a fork seal yesterday on the Jericho to Assen sand road on one of the washouts I guess  :biggrin:

I always keep a spare fork seal, so no going to BMW today (none left now), but I thought I would document it to show how simple an exercise it is on the pigs… 8)

Tools needed, 3mm allen key, 22mm open end spanner,  14mm socket 6 point 12 point rounds the nuts, this is a 6 point do we understand ::)

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Taking an edge or small screwdriver prise out the cover, it should come easily

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This is the nut you need the 14mm 6 point for

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Hold the stanchion hex with the 22mm spanner and undo the 14mm nut

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Push the stanchion down it should go easily and out of the way of the top triple crown

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Withdraw the complete stanchion

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Prise out the dust seal/scraper should also come out easy

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You will see the seal and its retaining clip,

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The clip comes out easily with a small flat head screwdriver

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Then using a flat screwdriver lever the seal change sides to ease it out if tight, note which way up, the spring is on top

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I then measure the volume of oil in the leg, each leg takes 450ml my calcs say 470mm of height I had 420mm on the piece of curtain rail measure, so I added 50ml, I use ATF its goods enough for these forks as they do not damp in the stanchions its lubrication only

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Push the new seal in by hand using the old seal to protect it

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Take out old seal and fit clip also by hand

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Oil the stanchion and fit scraper

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Oil the seal lip and gently insert the stanchion

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Loosen this screw to bleed air as you push stanchion into roughly the right height to fit into top yoke

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Tighten screw and push thread into bearing

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Refit nuts and cap (BMW say that nut should get Loctite your choice)

forkseals023.jpg


Done
 
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