1992 K100RS 4v fork seal and oil change

[Ryeguy74]

Hey guys, so right now my bike is apart meaning front tire and the bridge for the calipers off.


Heres my issue
Ive been watching IllinoisBMWRiders for everything on this bike as I can really understand after watching him, he is very good w explaining things.  He has a k1200lt that he works on and up until now even though different repairs have been just about the same, up until now.


So my left side fork is leaking so i was all set to replace it, watched his video a dozen times and went to it realizing things were a bit different. His lower fork came right off and he just was able to do the whole seal and oil change that way 1 2 3. 


That is not the situation im having.


Those lower forks are stuck on there and will not budge, looling into it more im seeing people saying that after a certain year the forks have to be taken off from the very top and the whole thing removed.


Anyone have a video or pics on what actually needs to be done to replace this? I was tugging away and theres no way this thing is coming off, not sure where to go from here, may have to put it back together and wait for another day or bring it somewhere to get it done bc now im pretty intimidated by the job ahead of me.


Any sort of pics, advice, or anything would be very helpful probably will put it away in an hour if i cant figure it out todya and save for another day but would love to finish todat

[Filmcamera]

Hi,

There is a nasty bolt in the very bottom of the forks, mine were totally messed up and I had to use an extractor to get them out.

However once those are out it is pretty simple.

Have you downloaded a manual from here yet? If not I suggest you do, actually two I'd get the manual for the K110-TS as well because the 16V K100RS much more closely matches the K100RS than it foe the earlier 2V K100's.

http://www.motobrick.com/index.php/topic,2253.0.html

http://www.motobrick.com/index.php/topic,2252.0.html

http://www.motobrick.com/index.php/topic,276.0.html

[Ryeguy74]

Hey! Thanks for the response im outside on my phone so ill have to go check these out, i was going to attempt to remove the drain plug but didnt want to stip it and wasnt sure if that would help. Is it all vacuumed on to there and once removed itll come off? Sorry i will defiently look into your links in a bit but figures id ask while atill trying to figure it out.


Also i do have a clymer manual but its just not all that clear to me as to what needs to be done, I was scared if i remove the fluid and have to bring it in somewhere that i wouldn't be able to jusr ride it there if all the oil is out.

[Filmcamera]

You do not have to remove the drain plug, the bolt I am talking about is the one that holds the top and bottom halves of the fork leg together.  Once that is out a sharp tug should separate the halves.

it is part number 13 in the diagram (though you need to check if you have part 16 - it swapped from one to the other in 8/91)

[Ryeguy74]

Okay I see so once that bolt is removed the lower fork will come right off?


Any idea how id be able to do that while leaving it still attatched to the bike? I would love to juat take that bottom half off of the bike but not too sure how it would be possible with it moving all over the place when turned. I will probably have to get a vice maybe there is some way to jerry rig that together.


So that is the bolt that you said can strip very easily? It looks like one gigantic PITA if that were to happen so i guess im going to need to do everyrhing in my power to prevent that, no clue how id get it out if that happened.


Im putting it together and away for now and going to try and think of some way to get that bolt off while leaving it on the vike, guess that is the only big issue keeping me from completing this.

[Filmcamera]

I think it would be pretty hard to undo it with the fork leg still attached to the bike. and even if you could I don't see how you are then going to have enough room to remove the lower half from the top half. 

[Ryeguy74]

Ok so quick update what I did was put the bridge back on that holds the brakes together, i made sure i was completly in there and i did manage to get the one bolt from the bottom out but damn was it in there. The other is giving me much more trouble and doesnt seem to budge, even though i did get the side that is leaking i think i may leave this for another day and may need to look into a pnuematic drill


Unfortuantley i dont have a garage and just a tent so im going to have to put it all back together and try again later and hope i can get the other side off.


Some of the oil started to come out and it was straight greay/blackish so im realizing now I should have changed this when i first got the bike a couple years ago but im really hoping its as simple as getting that bolt off and popping the entire thing off. Im still hesitant to try it now mostly bc im burning daylight and have places to be tomorrow and cant just let this sit outside for a couple of weeks if something goes wrong.


Any more pics, videos or advice is always welcome, I always get nervous with this stuff so any guidance it appreciated, hopefully a pnuematic can get that other pesky bolt off.

[Ryeguy74]

Filmcamera, I think i may be misunderatanding how this whole thing comes apart then, im under the impression that where i see the dust boot that bottom half will just pop right off when this bolt is removed, is that correct or am I overlooking something?


My set up now is the bike is on the center stand and i have a jack underneath the front of it so i can lift it up so my thinkinf is I can remove that lower fork by jacking the bike up enough to remove it.


I have a feeling im definetly over looking something, ill try to get some pics and put up my thoughts on the computer later and see if I have the right idea or not.

[Filmcamera]

There might be enough room to remove the lower half of the fork leg if you are lucky, I am not sure.  The top half sits at least 6 - 9 inches inside the bottom half if memory serves.

I took mine off to get to the seals and replace them and it wasn't really a big deal taking them off the bike and it certainly made working on them much easier afterwards.

I don't really have any pictures of the actual seal replacement procedure except the one that is attached which does not really help much but does show the old seal and retaining ring.

[Fstntq]

Just checking in with folks who have BTDT.  I'm looking for the proper orientation of the washer just below the oil seal and above the bearing seen in the previous post.  My issue is K1 specific but I think it shares the front forks wit the K100RS/  The washer is domed and I need to know if the dome goes up or down.

Also best way to minimize light fork scoring.  Steel wool?  Perhaps emery cloth/ sandpaper but what grit?
thx
MIke