Fork seals 1992 400SF FII(N)

[bpec]

I didn't find any relevant info in the search option, so a query.
Is it handier, or is it needed, to remove the complete fork from the steering head to do the dust/oil seals or can you get away with just removing the sliders? If you can, is there any benefit or anything to watch out for?

Many thanks, Pete.

[Superjack44]

When I did mine I removed the forks from the bike.
Tip before you slacken the fork clamps slacken off the allen bolt that retains the damper the bolt is accessed once the axle bolt is removed and an allen key/socket is inserted directly under the fork leg and up through the axle bolt hole.
Make sure you have a good tight fitting key/socket you dont want to round off the head, a windy hammer gun can be useful for that first initial crack off to loosen the bolt.

[bpec]

Thanks for the reply SJ44, I did the same as yourself then saw a guy on utube showing the slider only removal method (after me having searched for long enough beforehand - Murphy's Law!)
Anyway complete fork removal gives better access to the stanchions (for whatever) and lets you know the state of the clamping bolts. I was missing one spring seat "washer" between the spacer and fork spring -- ?? and the bottom bolt and washer into the bottom of the fork piston looked "sound", so they'll do if I cant pick up replacements.
The bushes looked sound, but I may not know. Do you know of any telltale indicators for deterioration?

pete.

[Superjack44]

Sorry cant really help there but I would have thought that by fixing the lower leg in a vice any wear present would be felt if you push/pulled the chrome stanchion back and forward.

[bpec]

Thanks for that.
pete

[cb400joe90]

Hello all. My 94 cb400 sf has just started to leak on the fork seals. Not sure if I can fix this myself. Has anyone any links to a youtube guide or a How to guide??? Also when the seals start to leak, is it a case of dont use the bike again until its repaired or would it be alright to ride the bike for a week or 2???

[tomigun]

I think for your safety it is good to repair the seals as soon as you can.When i replace my lower boots i found that in youtube,and i think it is very usefull : http://www.youtube.com/watch?v=5A0p2OH6FmI
When you go to fit the new oil seals you can use a pvc pipe bigger than 41mm diameter that your fork pipe is and about 100cm long and a plastic hammer to mount the oil seal in the correct place.After that dont forget to fit the metal ring and finally the new dust seal.

[cb400joe90]

Thanks Tom. Video is very useful. He mentions the fork is from a fireblade. Can I expect the components to be the same as my 1994 cb400 super four? Its a pity he doesn't do a video of reassembly for idiots like me. At what stage do you refill with oil? Ill really have to do more investigation into this before I attempt it. Local mechanic could do it for me for 100 euro but thats 100 euro I dont really have to spend.

[tomigun]

Unfortunately our components is not one piece like the video,so you must be careful.
Look this picture.

After removing the top bold(17) and drain the old oil,you take the metal ring (26),the stanchion pipe(3) the metal ring (4),the fork spring (2),metal ring (13),the fork damper(14),the rebound spring (10) and finally the oil lock piece.
After that you can remove the old dust seal (25) and the stopper ring (15).
Then using quick successive motions pull the fork pipe out of the lower boot.
After 5-6 moves you must pull out the old oil seal and the buck up ring(7).And it is time for clean everything.
Check the slider bushing(9) and the guide bushing(8),if it is in good condition.
Replace if necessary.
Install the buck up ring (7),the new oil seal and the fork tube into the lower boot.
Install the rebound spring(10)and the oil lock piece onto the dumper(14)
Be careful here,the oil lock piece is like a small aluminium glass.The lower piston dumper edge must be inside that glass.

I mention that part because when i separate the fork tube from the lower boot,that oil lock piece was stuck inside
and it pulled out with the fork tube,fell on the table and i was very confused about the correct fit of that part.
After that you have to install the bottom bolt (22) and drive the new oil seal into the lower boot until the stopper ring groove is visible.For that work i use a pvc plastic pipe and a plastic hammer that i mention before.
Install the stopper ring into the groove and the new dust seal.And now you can fill up the new oil to the fork.
The superfour with original oem springs the amount is 499ml for each fork tube.If you have after market springs you must follow the instructions.
And finally we have to install metal ring(13),fork spring(2),metal ring (4),stanchion(3)metal ring(26)and top fork cap(17). Now you have the other fork!!
You will need a clean space to work.And about the mechanic he asked me about the same amount. 100 euro but thats 100 euro I dont really have to spend also.(Damned Crisis). Wish you happy assembly.

[cb400joe90]

Thank you again Tom. Fantastic amount of detail. I feel more confident in trying this myself now. Im afraid I can see the crisis lasting at least 10 more years in Ireland anyway. At least you have that great sun shine in Greece