One of the front fork seals on my K100 is leaking; so bad that it is time to relace. Looked at the manuals but the drawings are indistinct. The seals have an open and closed end. The open end has the little coiled spring inside. On the one fork; the seal's closed side is uppermost and on the other, the open end is uppermost. Which is the correct one?

the closed end of the seal should be towards the top  on both

gunsports wrote:One of the front fork seals on my K100 is leaking; so bad that it is time to relace. Looked at the manuals but the drawings are indistinct. The seals have an open and closed end. The open end has the little coiled spring inside. On the one fork; the seal's closed side is uppermost and on the other, the open end is uppermost. Which is the correct one?

   If the springy thingy side is up it's no wonder it's pissing oil. Might stop water getting in though.

Great And the seals were replaced by the AGENTS  not one year ago!

The info given by the other guys regarding the closed side of the seal being uppermost is (of course) correct.  The bit of your post that intrigues me is the 'fork seals - again!' bit.  When did they last fail?  If they have failed in a short time frame, then there must be some reason as they ought to last for many thousands of miles (if properly installed).  Are the stanchions pitted, or scabbed with rust?  If so, some gentle polishing with the finest grade of steel wool can get around the problem.  If you intend to have the bike for years to come, why not install fork gaiters when the seals are done?  As long as the looks do not offend you, then gaiters are a solution many find that works for them.

Crossed post:  A year eh?  If the seal was upside down, I am surprised it lasted that long.  Another example of why we should do maintenance ourselves if we can - that way we know whether it has been done.

The "again" part was an admission from a member too lazy to do a search!

The bike had stood for 12 years; and was taken to the agents to be 'put it back on the road'. They made a hash of it; including fitting the fork seal upside down. When I got the bike, I replaced the fluids, including the fork oil. The affected fork was dry and this affected handling. Since replacing the oil, the seal is leaking and I guess the oil level is low again as I can feel the bike is 'diving' under hard breaking. I ordered a seal set from Moto Bins, which has now arrived.

The forks themselves are in a very good condition. No rust, no roughness and no marks.

The new seals; correctly installed, should rectify the problem.

I agree about doing your own maintenence and repairs. Leaving it to ohers will make you go broke quickly on a classic bike.

When I was with Honda Australia we had a dealer workshop send a 550 four to us because they couldn't get it to run right and the tacho didn't work. So I lifted the top of the engine and just as I thought the cam shaft was in backwards (turned over side to side) so the tacho drive wasn't even connecting to the cable and the wonder of wonders is that it actually ran, sort of.
It had always been hard to get good bike mechanics anywhere.  Once when I was in Darwin on holidays I let it be known that I knew about Hondas at the Honda dealer when I went in to buy oil and filter he tried to get me to work there and actually stood in the door way and jokingly said he wasn't going to let me out till I said I would work for him.
Apparently he had quite a few bikes to fix and no mechanic and no prospect of getting one.

This long weekend (another bloody public holiday!) is scheduled for a fork seal replacement. As this will be a once off, is there any advice as regards the flushing of the forks? Some have suggested fork oil. What about paraffin or a simmilar, non solvent mix?

The best thing about using fork oil and giving it a second change is that you will not get all the old oil out and if you use a solvent or paraffin you will have some of it left in there.

agree fork oil would be the best choice

just flush a bout 50mm or so in after draining the old stuff .....work the forks a bit and then drain the dregs ...I would imagine you will have the fork legs out so possibly will have a good chance of scavenging a good amount out the drain holes

good luck....!  got my fingers crossed that all goes well

I use brake cleaner. No worries about it leaving traces as it evaporates away.

Been reading up on the procedure (Yes, I'm a noob, so I read the manuals!). Is it really necessary to remove the front wheel? No easier route?

Been thinking of removing the instrument cluster and all those bits; the brakes and mudguard and then dropping the forks out. Or am I lazy here?

Just asking .....

prop the motor under the sump with some kind of jack whilst on centre stand
pop the wheel out
drop the calipers off , but support their weight ....(hockey straps are good for this )
undo the mudguard - brake line clips and remove
undo - loosen  bolts on forks top and bottom of triple tree

you may have to lever - spread a little  but the forks should just pull out

safety ropes connected to the handle bars from the roof might be a good thought ...saves toppling over ? 
don't see any reason for instruments off to do this job

On an 8v K, I just undo the bottom slider retaining screw and leave the stanchions in place. Just be certain that the main stand is on a block of wood to ensure enough clearance to allow the slider room to clear the stanchion base.

good idea mike

charlie99 wrote:
undo - loosen  bolts on forks top and bottom of triple tree

you may have to lever - spread a little  but the forks should just pull out

Hey Charlie. Those damn upper triple-tree bolts were way over-tightened by some #!@&* :pirat:  mechanic at the dealer's where I bought it. I tried my best, impact wrench too, but could not get them loose. Any thoughts?

Heat. Apply heat to the clamp particularly around the screws.

Once you get them out, throw them away and replace them with some stainless bolts with full thickness heads.  That's what I do.

yeah a common problem with "galling "  steel on aluminium aj
a lot of us use some form of thread anti-seize  after you do get them out

I wouldn't think that the po intentionally did them up too tight ...its just a fact that galling does occur on dissimilar metals

I tend to use a 3/8 drive with allen key adaptor these days .....you do get a lot more purchase on the screw "first time " rather than using a shorter allen key and screwing up the internals when the tensions required exceeds the length and or torque available of the key alone

of corse we know that the shock principle does work well , that is you get a drift of some type and hit the head of the screw possibly a few times with a good sized hammer  ,,,,,the sharp wrap on the head transfers the energy of that to the threads  (heating effect )  ..quite often loosening - breaking the galling section

on the triple clamps I would be using some thing like a panel beaters dolly ...or 3 pound hammer on the other side of the screw length to offer some resistance to the impacts and let the shock event work properly

you may need to find a second set of hands to achieve this

good luck ...no easy solution ... 

mikes suggestion is also a good option as well ...and I have planned to get a porta gas type bottle again ( had one years ago ...went out of date  and had to throw it )

hope that helps

I used heat and an imperial size allen key hammer'd into the damaged hexagon. Replaced allen screws with normal hex head bolts, with extra washers under the head to clear the counter sunk holes. Be careful tightening  as you can now get a lot of leverage on a spanner or socket. John

'Did' the fork seals this morning. In the end, not the huge job I thought it would be. Fact is, removing the seals were the most difficult job. But, they came out without damage to the fork bodies. The rest was easy. Took the bike for a spin and all seems well. Tips for all the advice.