Friday, May 13, 2011

R1150GS Fork Seal and Dust Seal Replacement

Replacing the fork seals or dust seals on an R1150 is pretty easy, and should only take 10-15 minutes. This is how I did it on my 2001 BMW R1150GS without removing the front wheel or forks from the motorcycle.

Tools I used:

R1150GS Fork Seal and Dust Seal Replacement

The new dust seals on the left and the oil seals on the right. I paid about $15 for each seal on bikebandit.com.

R1150GS Fork Seal and Dust Seal Replacement

This is the order of all the parts in the fork tube on the bottom, left to right: washer, oil seal, retaining clip, dust seal, *not shown fork nut 14mm*, fork cap

R1150GS Fork Seal and Dust Seal Replacement

1) put the bike on the center stand to make the front wheel easy to move around.

R1150GS Fork Seal and Dust Seal Replacement

2) Remove the re-usable ziptie holding the brake or clutch cable depending on which side.

R1150GS Fork Seal and Dust Seal Replacement

Press the tab back towards it to pull it apart.

R1150GS Fork Seal and Dust Seal Replacement R1150GS Fork Seal and Dust Seal Replacement

R1150GS Fork Seal and Dust Seal Replacement

3) Remove the cap on the top of the fork with the flat blade screwdriver by inserting it into the slot

R1150GS Fork Seal and Dust Seal Replacement

R1150GS Fork Seal and Dust Seal Replacement

R1150GS Fork Seal and Dust Seal Replacement

4) Using the 14mm socket and 22mm wrench, remove the nut on the top of the fork tube. I used a 7/8” as shown below.

R1150GS Fork Seal and Dust Seal Replacement

5) Push the fork slider into the stanchion and then pull it out. The front wheel will freely move side to side to make this very easy.

R1150GS Fork Seal and Dust Seal Replacement R1150GS Fork Seal and Dust Seal Replacement

R1150GS Fork Seal and Dust Seal Replacement

Have a rag handy as the slider will likely drip fork oil as you pull it out. Wipe it clean, and set it aside in a safe place where it won’t be scratched.

R1150GS Fork Seal and Dust Seal Replacement

6) Use the flat blade screwdriver again and remove the dust seal on the top of the stanchion.

R1150GS Fork Seal and Dust Seal Replacement

R1150GS Fork Seal and Dust Seal Replacement

Both of mine were split and cracked (and leaking). I’d recommend replacing them along with the oil seals.

R1150GS Fork Seal and Dust Seal Replacement

8) With the needle nose pliers, pull out the retaining clip

R1150GS Fork Seal and Dust Seal Replacement

9) With the seal puller, remove the oil seal.

R1150GS Fork Seal and Dust Seal Replacement

If you don’t have a seal puller, get one. It makes this part take five seconds (literally) with no damage to the fork tube versus trying to lever (and bend) with a screwdriver or something else. I bent two different screwdrivers, but didn't get the seal out. I've also read you could screw wood-screws into the bad seal and pull it out with a pliers. The seal puller did the job for me.

the leaky oil seal aka fork seal

R1150GS Fork Seal and Dust Seal Replacement

position under the fork seal

R1150GS Fork Seal and Dust Seal Replacement

R1150GS Fork Seal and Dust Seal Replacement

pull up slightly and it will pop right out

R1150GS Fork Seal and Dust Seal Replacement

remove the seal

R1150GS Fork Seal and Dust Seal Replacement

the damage to mine is clear here:

R1150GS Fork Seal and Dust Seal Replacement

new fork seal aka oil seal below:

this is the top view:

R1150GS Fork Seal and Dust Seal Replacement

this is the bottom view:

R1150GS Fork Seal and Dust Seal Replacement

10) seat the new seal with a socket. A little fork oil on the seal makes it easy to start by hand. Make sure to insert it with the bottom side down.

R1150GS Fork Seal and Dust Seal Replacement

Get a socket that is the same diameter as the outside of the oil seal, and that fits inside of the tube. You want to push on the hard outside, not the soft inside of the seal. I used a 3/4” to 1” impact adapter I found at harbor freight. A 34mm or 1 3/8” socket might also work.

R1150GS Fork Seal and Dust Seal Replacement

Put an extension on it and pound it home.

R1150GS Fork Seal and Dust Seal Replacement

R1150GS Fork Seal and Dust Seal Replacement

11) reinstall the retaining clip

R1150GS Fork Seal and Dust Seal Replacement

12) install the new dust seal by pressing it into place

R1150GS Fork Seal and Dust Seal Replacement

13) use the 3mm allen wrench and remove the little bleed screw near top of the fork slider

R1150GS Fork Seal and Dust Seal Replacement

be careful not to lose or damage the tiny o-ring

R1150GS Fork Seal and Dust Seal Replacement

R1150GS Fork Seal and Dust Seal Replacement

14) push the slider all the way into the fork tube and then pull it back up to the top yolk in its final position. Air should rush out the bleed hole. I repeated this twice.

R1150GS Fork Seal and Dust Seal Replacement

15) replace the bleed screw and hand tighten until snug. This is a small screw, so be careful not to over tighten.

R1150GS Fork Seal and Dust Seal Replacement

16) Replace the nut. Using the 14mm socket and 22mm wrench tighten. If using a torque wrench, tighten to 45Nm.

R1150GS Fork Seal and Dust Seal Replacement

17) Replace the top cap and re-usable ziptie.

R1150GS Fork Seal and Dust Seal Replacement

18) Repeat on the other side.

19) Go for a ride!

 

If you want to also replace the fork oil, use BMW fork oil grade 7.5 and put 15.8 oz. of fluid in each fork.

R1150GS Fork Seal and Dust Seal Replacement

 

Other R1150GS Guides:

6 comments:

  1. Good write-up and description of the process. I have been procrastinating on my old bike. It is also a pretty quick process but the wheel and fender needs to be removed. How often should the fork oil be replaced?

    ReplyDelete
  2. RichardM: Thanks! Good question too. My haynes manual said to remove the front wheel and such, but it seemed like way too much work. (especially after the above method)

    My manuals don't mention an interval for fork oil changing on the BMW, and I don't see it on any maintenance schedule online. I'm guessing since mine is a telelever setup and the forks don't actually do anything other than assist steering, the oil isn't as important as in other bikes.

    For other motorcycles with normal forks, a quick search on the internet seems to be every other year.

    ReplyDelete
  3. Nice job Chris, it really does look pretty easy.

    As to how often, I dimly recall my beemer mechanic saying something like at every major service, which is every 10K miles.

    dom

    Redleg's Rides

    Colorado Motorcycle Travel Examiner

    ReplyDelete
  4. Dom: Thanks. It is easy and fork oil is cheap. Now if only all my bikes used the same weight!

    ReplyDelete
  5. Chris: Great post, best set of nstructions I found anywhere. very detailed and photos are the best. Couldnt have done without them.
    Was able to do seal replacenment without taking the wheel/fender off.
    All other instructions are great too. Thanks a lot for posting them.
    One addition will be helpful - what' the oil level supposed to be? Mine was leaking for sometime so I thought I would add some oil but didnt know how much. I must hav added a little too much because when I inserted the tube and moved it up and down a couple of times as suggested, oil squirted out from the top screw hole. Big mess, Lesson learned!

    ReplyDelete
    Replies
    1. Thanks! I'm glad you found it useful. I like to write them in the way I'd like to use them. :)

      15.8oz in each fork is the recommended amount from BMW. See the very last photo.

      Delete