Changing an 1150 GS fork seal

[kevbo]

Here is a quick procedure, doesn't even require removing front wheel. You do have to work inside the beak. I'm 6'5" and if I can get my big hands in there, anyone should be able to.

Sorry, no pictures, I did this in the dark, and it was windy, and didn't want delays adding to the grit.

Changing a 1150GS fork seal should be a 30 min. chore the first time, and maybe only 15 minutes the second time. Bout $30 in parts including a quart of BMW fork oil.

Step-0) put bike on center stand.

Step-1) Remove the cable clip which is around the top of the fork leg. That is not a normal zip-tie, don't cut it. It is reuasable, there is a small release tab. This is perhaps the most time consuming part of the job.

Step-2) Pry out the cap on the top of the triple-clamp. I used a pocket knife.

Step-3) Hold the fork leg with a 22mm open end wrench, and use a 14mm socket to remove the nut that was under the step-2 cap.

Step-4) Push the fork leg down, then bring it forward. Have a rag ready to put under bottome end which will be dripping oil. Then pull the leg upward and out. Be careful not to drop or scratch it.

Step-5) Pry the dust seal out of the slider. knife blade again to start it, small screwdriver to finish it.

Step-6) Remove the small wire clip which holds the seal in place. Small allen wrench makes good tool. DON'T drop it down the slider. Note that the seal is positioned so that the garter spring is visible.

Step-7)pry the old seal out. Screwdriver job. Use twisting motion rather than prying on edge of slider.

Step-8)
Either suck out, and replace the fork oil (470cc of BMW 7.5Wt.) or guess at how much came past the leaky seal, and squirt that much in there. Error on the skimping side.

Step-9)Install new seal, I used a 5/8" fender washer on a long bolt to push it home. Hand pressure was enough, no need to pound. Garter spring goes on top side.


Step-10) Put everything back togethor. Don't forget the snap ring.
Locktight on the top nut., torque to 45 Nm (~32 lb-ft) Yer done.

[RubberDown]

sounds pretty painless. I don't remember ever seeing a service interval for replacing the fork oil...and there is no drain plug. Is that a "fill for life" kinda deal?

Eric
'01 R1150GS

[kevbo]

There is a drain plug, AND it is supposed to be service free. Since the oil is not used for damping, it doesn't break down.

I looked like the slide bearings were some sort of plastic....nylon or maybe even teflon.

[Curmudgeon]

Great advice, that matchs what the tech said at the local BMW dealer... Except!

Step-8)
Either suck out, and replace the fork oil (470cc of BMW 7.5Wt.) or guess at how much came past the leaky seal, and squirt that much in there. Error on the skimping side.

The manual says:

Telescopic fork oil

– approved grades BMW telescopic fork oil

BMW Fork oil: 7.5 Wt

BMW Telescopic Fork oil: 10.0 Wt

Airhead fork oil is 7.5 Wt, but Oilhead Telescopic is 10.0 Wt.

Patrick

Live Long and Ride

Originally Posted by kevbo

Here is a quick procedure, doesn't even require removing front wheel. You do have to work inside the beak. I'm 6'5" and if I can get my big hands in there, anyone should be able to.

Sorry, no pictures, I did this in the dark, and it was windy, and didn't want delays adding to the grit.

Changing a 1150GS fork seal should be a 30 min. chore the first time, and maybe only 15 minutes the second time. Bout $30 in parts including a quart of BMW fork oil.

Step-0) put bike on center stand.

Step-1) Remove the cable clip which is around the top of the fork leg. That is not a normal zip-tie, don't cut it. It is reuasable, there is a small release tab. This is perhaps the most time consuming part of the job.

Step-2) Pry out the cap on the top of the triple-clamp. I used a pocket knife.

Step-3) Hold the fork leg with a 22mm open end wrench, and use a 14mm socket to remove the nut that was under the step-2 cap.

Step-4) Push the fork leg down, then bring it forward. Have a rag ready to put under bottome end which will be dripping oil. Then pull the leg upward and out. Be careful not to drop or scratch it.

Step-5) Pry the dust seal out of the slider. knife blade again to start it, small screwdriver to finish it.

Step-6) Remove the small wire clip which holds the seal in place. Small allen wrench makes good tool. DON'T drop it down the slider. Note that the seal is positioned so that the garter spring is visible.

Step-7)pry the old seal out. Screwdriver job. Use twisting motion rather than prying on edge of slider.

Step-8)
Either suck out, and replace the fork oil (470cc of BMW 7.5Wt.) or guess at how much came past the leaky seal, and squirt that much in there. Error on the skimping side.

Step-9)Install new seal, I used a 5/8" fender washer on a long bolt to push it home. Hand pressure was enough, no need to pound. Garter spring goes on top side.


Step-10) Put everything back togethor. Don't forget the snap ring.
Locktight on the top nut., torque to 45 Nm (~32 lb-ft) Yer done.

[johnjen]

One additional note for all of you that have done this... No one mentioned bleeding off the air pressure from the re-assembled front forks... That will change the handling considerably... Just a thought..

JJ

[Nailhead]

What on Earth is fork oil doing in a suspension like the T-lever? I thought that neat little external shock/spring negated the need for fork oil, seals, and the mayhem they INEVITABLY cause? I thought I was exempt from this!
- Chris

[johnjen]

The oil is for lubrication, not for hydraulic dampening. Less stiction that way.

JJ

[DruiD]

I just did mine. What a breeze! I can't believe I probably spent more time wiping oil off my forks than I did changing the seals!

[Bill the Bong]

Originally Posted by johnjen

One additional note for all of you that have done this... No one mentioned bleeding off the air pressure from the re-assembled front forks... That will change the handling considerably... Just a thought..

JJ

I agree. I took out the little grub screw with the o-ring at the top of the stansion while sliding it into the lower leg. Lot of air rushing out while pushing the stansion in. Don't know if not doing that would lead to the seal blowing out though

Bill

Bill

[johnjen]

Originally Posted by Bill the Bong

I agree. I took out the little grub screw with the o-ring at the top of the stansion while sliding it into the lower leg. Lot of air rushing out while pushing the stansion in. Don't know if not doing that would lead to the seal blowing out though

Bill

Bill

The BMW manual calls for releasing the air with the tubes fully extended (ie on the center stand).

JJ

[matkal]

Just did mine, very easy job. Thanks for the tutorial!

I just left the old fluid(PO used ATF) in there,
only one of my seals where leaking so I dumped a capfull in the non
leaking side and measured with a (clean) paint stirrer and a closepin,
and added to the other side to match. It's easy to see down there as the inside of the tube is white.

I used an automotive drum brake adjusting tool(kind of an S shaped prybar)
and a piece of hard rubber to protect the slider, to pry out the seal.

It took me about an hour.

[Mr Head]

Originally Posted by Nailhead

What on Earth is fork oil doing in a suspension like the T-lever? I thought that neat little external shock/spring negated the need for fork oil, seals, and the mayhem they INEVITABLY cause? I thought I was exempt from this!
- Chris

Without that oil in there the bike would wheelie way too easily.

[matkal]

Originally Posted by Mr Head

Without that oil in there the bike would wheelie way too easily.

And then you'd be replacing the fork seals more often.

[Mr Head]

Originally Posted by matkal

And then you'd be replacing the fork seals more often.

Hahaha, But, I know a "card trick" which usually works rather than just replacing the seal.
The other trick is to land the wheelie right. BMW is not replacing broken frames like on the gixxer one millions.

[JTM65]

Can anyone tell me where to bleed the air out of the fork? That might explain why the front end on my 00 feels like the shock is a solid bar bolted in there. PO might have replaced a seal and not let the pressure out.