85 R80RT fork seal replacement

[BMW Kurt]

I need to replace my front fork seals on my '85 R80RT and would like to know if there is a tutorial or something here on this site. I have done this before on an R90S and do not remember it as being as difficult as Clymer describes. Clymer calls for removal of the fairing and total disassembly of the forks if I am reading it correctly. All I need to do is replace the turquoise colored seals. I think when I did this before all I had to do was remove the lower forks.

Any links to help a fellow out??

[squiffynimrod]

[BMW Kurt]

Hmmm! Maybe I need to rephrase my question.


Do I really need to dismantle the fairing and entire front fork assembly to replace the fork seals on an '85 R80RT?

I replaced the fork seals on an R90S once and I swear it only took a couple of hours (if that!).

[bmwrench]

Renewing the fork seals in your current bike is not a lot different than on your R90S. Remove the front wheel and fender, then remove the 8mm bolt that retains the slider, which is visible once the axle is removed. You may need an impact wrench to remove these screws because the damper rod tends to rotate with the bolt. Once the bolts are out, pull the sliders and fork brace as one. Renew the seals. Reassemble and refill the oil through the holes at the top of the fork.

[boxerboy81]

This is what I do for a 1982 model R100RS.

Changing BMW fork Seals/ springs/ gaiters/ oil

Nomenclature: I call the chromed tube the fork tube. The fork leg is the lower forged bit that the calipers attach to.

1. Put new seals in the freezer for 1 hour beforehand.
2. Loosen, remove, the top fork bolt to allow drainage and refill of fork oil..move h/bars to get to bolt.
2a. To replace the springs, you need to remove the large hex bolt at the fork top, therefore no need for point 2. That bolt is very tight and easy to round off. Make sure your tool fits well.
3. Remove the lower drainage small bolt. Allow oil to drain.
3a. Replace springs, loosely replace top bolt.
4. Disconnect brake calipers from fork legs...hang carefully.
5. Loosen, don't remove, the retaining bolt at the bottom of the fork. You get better leverage before the axle comes out.
6. Remove axle/wheel/front guard.
7. Now remove retaining bolt, drop fork leg down, leaving the fork tube on the bike. Remove old gaiters/boots.
8. Clean fork leg internals.
9. Carefully lever out the old seal. I use a blunted straight screwdriver. You must not score the inner surface of the fork leg where the seal sits. Insert the cold new seal, use old seal to seat the new seal.
10. Slide upper gaiter spacer then gaiters onto fork tube.
11. Install fork leg with new seal carefully over the fork tube..
12. etc, etc...both sides
13. Reinstall drain bolt, refill oil, tighten top bolt.
14. wheels etc back on...
15. fiddle with the gaiter spacer, locate it into the breather tube on the inside of the lower triple clamp.
One hour max. Quicker the next time.

[BMW Kurt]

Originally Posted by bmwrench

Renewing the fork seals in your current bike is not a lot different than on your R90S. Remove the front wheel and fender, then remove the 8mm bolt that retains the slider, which is visible once the axle is removed. You may need an impact wrench to remove these screws because the damper rod tends to rotate with the bolt. Once the bolts are out, pull the sliders and fork brace as one. Renew the seals. Reassemble and refill the oil through the holes at the top of the fork.

Originally Posted by boxerboy81

This is what I do for a 1982 model R100RS.

Changing BMW fork Seals/ springs/ gaiters/ oil

Nomenclature: I call the chromed tube the fork tube. The fork leg is the lower forged bit that the calipers attach to.

1. Put new seals in the freezer for 1 hour beforehand.
2. Loosen, remove, the top fork bolt to allow drainage and refill of fork oil..move h/bars to get to bolt.
2a. To replace the springs, you need to remove the large hex bolt at the fork top, therefore no need for point 2. That bolt is very tight and easy to round off. Make sure your tool fits well.
3. Remove the lower drainage small bolt. Allow oil to drain.
3a. Replace springs, loosely replace top bolt.
4. Disconnect brake calipers from fork legs...hang carefully.
5. Loosen, don't remove, the retaining bolt at the bottom of the fork. You get better leverage before the axle comes out.
6. Remove axle/wheel/front guard.
7. Now remove retaining bolt, drop fork leg down, leaving the fork tube on the bike. Remove old gaiters/boots.
8. Clean fork leg internals.
9. Carefully lever out the old seal. I use a blunted straight screwdriver. You must not score the inner surface of the fork leg where the seal sits. Insert the cold new seal, use old seal to seat the new seal.
10. Slide upper gaiter spacer then gaiters onto fork tube.
11. Install fork leg with new seal carefully over the fork tube..
12. etc, etc...both sides
13. Reinstall drain bolt, refill oil, tighten top bolt.
14. wheels etc back on...
15. fiddle with the gaiter spacer, locate it into the breather tube on the inside of the lower triple clamp.
One hour max. Quicker the next time.

Thanks! That's what I was looking for!

[BMW Kurt]

Originally Posted by boxerboy81

1. Put new seals in the freezer for 1 hour beforehand.

9. Carefully lever out the old seal. I use a blunted straight screwdriver. You must not score the inner surface of the fork leg where the seal sits. Insert the cold new seal, use old seal to seat the new seal.

Just out of curiosity... why put the seals in cold? Do they contract in the freezer making them easier to put in and then swell to make a better fit??

[supershaft]

It seems that everyone is missing the hardest part: removing the snap ring above the seal. I use a tiny Vise Grip that I ground on a bit to remove the seal out from under the snap ring and then remove the snap ring. If your careful, it can be done without gouging anything. I have seen some muffed up sliders for people trying to get theose snap rings out the hard way. Good luck!

[bmwrench]

Originally Posted by supershaft

It seems that everyone is missing the hardest part: removing the snap ring above the seal. I use a tiny Vise Grip that I ground on a bit to remove the seal out from under the snap ring and then remove the snap ring. If your careful, it can be done without gouging anything. I have seen some muffed up sliders for people trying to get theose snap rings out the hard way. Good luck!

That might be because his bike doesn't have a snap-ring above the seal.

[BMW Kurt]

Originally Posted by supershaft

It seems that everyone is missing the hardest part: removing the snap ring above the seal. I use a tiny Vise Grip that I ground on a bit to remove the seal out from under the snap ring and then remove the snap ring. If your careful, it can be done without gouging anything. I have seen some muffed up sliders for people trying to get theose snap rings out the hard way. Good luck!

Originally Posted by bmwrench

That might be because his bike doesn't have a snap-ring above the seal.

Thanks! Scared the hell out of me for a second!

[supershaft]

Originally Posted by bmwrench

That might be because his bike doesn't have a snap-ring above the seal.

That could be it! Sorry everybody. I got my later model forks mixed up.

Thanks!