R 1100 RS Fork Seal issue

[weschmann]

Sorry to ask again about fork seals but I've used the search button with no results. My right side fork is leaking still, after changing out the seal and dust cover. I used the lower fork tube removal method, changed the seal, reinstalled following the method of using some dental floss to create an air escape, and ended up getting a little of the tape stuck in the tube upon assembly. Naturally it leaked, so I pulled it apart found what I thought was the issue and reinstalled, using nothing to create any air release. No issues with trapped air keeping the two parts from contracting to bolt back together. Still leaking. I'm told by the dealer that the bushing under the large washer may be bad so have the bushing on order. None of the videos on the 1100 varieties, whether R, S, RS, or GS show any issues with that bushing being replaced or how to remove or if possible to remove. Any suggestions? Thanks for any help. I thought this would be a simple issue to deal with and have changed fork seals in a previous F 700 GS, so not completely new to fork seals but not a lot of experience trouble shooting either. Since there isn't much air resistance when reassembling I'm assuming there's not much to keep the oil from pushing out of the seal. As additional info, I filled with 10 weight bmw fork oil and 470 ml volume.

 

[m_stock10506]

I'm sure you know that the oil in the forks is there only for lubrication, not for damping.

There is a 3 mm air bleed screw at the top of the fork. You have to cut down a hex key for it to fit under the handlebar to open or close it for air release.

You may have a nick or a scratch on the tube that is cutting into the seal. I would pull the slider off again and then check the tube carefully. Dress it with a 1000 or 2000 grit wet/dry emery paper. Put in a new seal. Install the seal with the open/spring side facing down towards the oil.

 

[weschmann]

I'm sure you know that the oil in the forks is there only for lubrication, not for damping.

There is a 3 mm air bleed screw at the top of the fork. You have to cut down a hex key for it to fit under the handlebar to open or close it for air release.

You may have a nick or a scratch on the tube that is cutting into the seal. I would pull the slider off again and then check the tube carefully. Dress it with a 1000 or 2000 grit wet/dry emery paper. Put in a new seal. Install the seal with the open/spring side facing down towards the oil.

Thanks for the reply Michael,
I haven't been able to find any air bleed screw on the fork but have taken the complete top off the upper fork, but truthfully I don't feel any resistance when I mate the upper to the lower to bolt back to the lower tree. I'm second guessing myself now if I've been putting the seal in upside down as I thought I was being careful enough to put back in in the correct orientation. I do remember seeing open /spring side facing up so (I thought when removing) but may have got that turned around as it was 95 degrees and 100 percent humidity the first time I took it off so that's a big possibility that I put the new seal in upside down. Interesting turn of events. Guess I'll wait till my next order of seals comes in along with the bushing and change out once again. Think I'll just take the whole fork out and do the work on the bench rather than on the bike. Thanks!

 

[weschmann]

94 R 1100 RS Fork Seal Orientation

Hi Michael, just wanted to double check about seal,orientation. I double checked my old seal and there is a wide groove on one side with no small spring around the circumference and on the other side narrow groove open with a flexible spring around it. In all the videos I see the spring orientated up towards the handlebars. You suggest the flexible spring should be orientated towards the oil or towards the bottom of the fork tube. Just checking to make sure I have my orientation correct, as currently I have the small groove facing up. I'll change it around tomorrow.

 

[m_stock10506]

Not great photos, but maybe they will help.

This is from my R1100RT. I am pretty certain that the forks and fork seals are the same for the RS. The seal photo is showing the bottom of the seal. You can see the spring inside the channel. This side goes DOWN into the fork slider facing the oil. I didn't realize that the top of the seal has a very shallow channel cut into it, but it appears to be mostly decorative.

The photo of the top of my fork tube is a little blurry, but I circled the 3 mm air bleed screw. The fork tube is able to rotate even when it is screwed into place, so the air screw could be hidden anywhere around the top of the tube. It should be there.

 

[m_stock10506]

Hi Michael, just wanted to double check about seal,orientation. I double checked my old seal and there is a wide groove on one side with no small spring around the circumference and on the other side narrow groove open with a flexible spring around it. In all the videos I see the spring orientated up towards the handlebars. You suggest the flexible spring should be orientated towards the oil or towards the bottom of the fork tube. Just checking to make sure I have my orientation correct, as currently I have the small groove facing up. I'll change it around tomorrow.

Wow, you made me second guess myself. I looked at a video and a photo layout just to be sure. The narrow channel is facing up, and the wide channel is facing down. The spring is in the groove of the wide channel and faces down. I have never seen a seal with the spring in the narrow groove.

Got this from Google:
Which side of the fork seals goes up?
Fork seals unquestionably, definitely, unequivocally, now and forever, absolutely always must be installed with the open side towards the oily bits - this allows internal fork pressure to tighten the seal; if reversed it will blow oil out every stroke. .Jun 7, 2007

 

[weschmann]

View attachment 84269 View attachment 84270

Not great photos, but maybe they will help.

This is from my R1100RT. I am pretty certain that the forks and fork seals are the same for the RS. The seal photo is showing the bottom of the seal. You can see the spring inside the channel. This side goes DOWN into the fork slider facing the oil. I didn't realize that the top of the seal has a very shallow channel cut into it, but it appears to be mostly decorative.

The photo of the top of my fork tube is a little blurry, but I circled the 3 mm air bleed screw. The fork tube is able to rotate even when it is screwed into place, so the air screw could be hidden anywhere around the top of the tube. It should be there.

. OK will reverse tomorrow. Thanks a bunch

 

[eastbay]

Thanks for the reply Michael,
I haven't been able to find any air bleed screw on the fork but have taken the complete top off the upper fork, but truthfully I don't feel any resistance when I mate the upper to the lower to bolt back to the lower tree. I'm second guessing myself now if I've been putting the seal in upside down as I thought I was being careful enough to put back in in the correct orientation. I do remember seeing open /spring side facing up so (I thought when removing) but may have got that turned around as it was 95 degrees and 100 percent humidity the first time I took it off so that's a big possibility that I put the new seal in upside down. Interesting turn of events. Guess I'll wait till my next order of seals comes in along with the bushing and change out once again. Think I'll just take the whole fork out and do the work on the bench rather than on the bike. Thanks!

Just completed the seal replacement on my K1100LT, where you have to remove the forks ,and installed Rancho gaiters instead of new dust caps. The inmates at Motobrick say they will greatly extend seal life. I've got to do the seals on my R1100RT and was considering doing it from the bottom too, but may now take them off and do it on the bench. I had a lot of trouble getting a rusted in snap ring out and doubt I could do it on the bike if the snap ring is similar on the R.

 

[weschmann]

Just completed the seal replacement on my K1100LT, where you have to remove the forks ,and installed Rancho gaiters instead of new dust caps. The inmates at Motobrick say they will greatly extend seal life. I've got to do the seals on my R1100RT and was considering doing it from the bottom too, but may now take them off and do it on the bench. I had a lot of trouble getting a rusted in snap ring out and doubt I could do it on the bike if the snap ring is similar on the R.

I would think based on my level of experience, taking the whole fork off and working on the bench is probably the better way to go. I have found that I damaged the seal while inserting the fork tube blind, with the dust cover in place so not going to do it that way when my next replacement comes in. A real mechanic can probably do it that way, but I don’t have the right touch so will do it the proper way . Actually in the long run it would have been easier to take the entire fork out than just the bottom. You experience level may allow you to just remove either the bottom or top, up to you.

 

[weschmann]

Thanks to all the suggestions. Think I finally have it done correctly.