Hi,

I hope someone can help me with this one??

The plan was to take the forks on my 21 apart for painting and new oil seals. One's done and after following the tips on the site and in a few of the threads, I took the dust seal off, then the circlip and then the allen bolt from the bottom of the fork leg and the first came apart after a few sharp tugs of the 2 parts.

The second is a total nightmare! after undoing all the same bits as above, it simply will not come apart! even with the leg held in the yolk and hitting it with a plastic faced hammer, the seal hasn't moved a millimetre.

Has anyone else come across this? Have I missed something?

Cheers and thanks for any help you can offer!

Jason

It should come apart like the first one, try holding the fork by the caliper mounts in a vice and give the stanchion a good hard tug using the full length of the fork travel as a run up (hope that makes sense) you might have to be fairly brutal and hammer it up and down several times.

Basically you just need to dislodge the seal and fork bush, if you still cant move it try gently heating the fork leg around the top in the area of the seal and bush.

If you still cant get it apart I can sell you a fork already in bits

Cheers Paul, I'll keep on trying then. I was worried I'd be causing some damage as I've been hitting it for ever!

Good to know you have afork I can buy though if I need one and Leigh has just offered to flog me some 28 forks also!

All the mc21 forks have the same stanchion and slider its only the internals that differ. If you do damage them you can pick up a set of r forks for next to nothing and install your se/sp internals.

I've had the same problem as you in the past.
I ended up drilling half way down the side of the seal and spraying penetrating oil into the holes. Eventually it came apart. I wasn't using the fork leg so it didn't matter about drilling down.
Corrosion between the seal and fork leg had kind of welded it in place!
Anyway, I've probably got a fork leg/slider kicking about you could have too, somewhere! Possibly not the one I drilled down either!
If you have the time, keep spraying penetrating oil on top of the seal over a couple of days. Then try again to dismantle it.

You can also try heating the outer where the seal is located with a heat gun or low heat blue flame, don't use a blow torch!

Cheers Chester, thats a kind offer that I may take you up on. I'll also keep it oiled until the weekend and give it another go then with a lump of wood and a bigger hammer!

Thanks also Alzazorg, I'll give the heat gun a go too if the oil doesn't work!

I'll let you know if i succeed!

Heat is the first thing you should try, I use propane torch, the type you would use to sweat the plumbing pipe together. Never heat the same spot too long, just rotate as heat is applied, usually takes 10 seconds to get it warm enough and then just POP! Never had a fork that wouldn't came apart once heated, and I've done at least a hundred.

Just read through your post again, do not hammer the fork! Pounding the fork with a hammer while it's clamped might do some damage to the tubes.

It should come apart with bare hands, just slam it apart. The only things you might damage when "slamming" are the teflon bushings, they are replaceable and cheap enough that you should consider doing them anyway. Also when heating keep in mind that its probably the teflon bushing that is stuck in the fork and not the seal, it's located just below the seal in the cast lower part so heat around there as well. Unless you use Oxy-Acetelene torch you will not easily damage the tube so if the heat does not work first time give it another go!

Cheers Dmitry, good advice that!

Nope!
It was definately the seal that was stuck in the fork I had problems with!
Water passing down through the dust seal and sitting in the area between the two seals caused corrosion.
The bush was well lubricated by the oil in the forks.
The bashing the bushes took whilst trying to seperate the fork did damage them, as mentioned earlier.
I wouldn't want to heat the aluminium leg with a naked flame. I'd use an electric heat gun.

Sorry mate, but have you had any training? I'm not a pro team mechanic but I've been trained to work on suspension, made a living doing it and been told to use propane torch.

It takes 1200F+ to melt aluminium, no chance you can get it that hot in 10-15 seconds. Just to help you visualize aliminium vs flame, think of the internals of you NSR engine where aluminium piston and aluminum cylinder are exposed to combustion temps well above the propane torch output.

I do want to warn you about using open flame near any flammable stuff like gas (pertol or whatever you call it)

Dmitry wrote:Sorry mate, but have you had any training? I'm not a pro team mechanic but I've been trained to work on suspension, made a living doing it and been told to use propane torch.

It takes 1200F+ to melt aluminium, no chance you can get it that hot in 10-15 seconds. Just to help you visualize aliminium vs flame, think of the internals of you NSR engine where aluminium piston and aluminum cylinder are exposed to combustion temps well above the propane torch output.

I do want to warn you about using open flame near any flammable stuff like gas (pertol or whatever you call it)

I wasn't having a 'pop' at you. More thinking of the cosmetic aspect of a naked flame on the fork leg. Granted raineyuk has said he is going to repaint the fork leg, not everybody will be doing this though.

My point was that in my case it was the seal sticking fast in the slider, not the bush.

I admit my method of removal was a bit 'agricultural' to say the least. Also, I wouldn't recommend others to follow that course of action either. Time, as always, was the deciding factor in my case.
Generally, I prefer not to deliberately damage/impair parts but, sometimes, you have to decide what your biggest priority is.

I,ve used oxy-acetaline torches, propane torches, braised, arc welded and mig welded. I'm not an expert at welding and don't really like doing it either.
I'm not a professional mechanic but, I've been trained by my father, who is. I've also worked in engineering since I was 17.
I've been building push bikes from age 10. Building motorbikes and rebuilding bike engines from age 13. Car repairs and cylinder head gasket/clutch changes, suspension/exhausts,fault finding,diagnosis,etc....since age 17.
Some so called "professional mechanics" leave a lot to be desired! In fact, due to my father warning me from a very young age, I just don't trust garages or mechanics as a matter of course. Last time my missus had a seasoned motor mechanic fit a bulb in her car, she complained to me that the beam didn't look right. When I checked, he'd forced it in upside-down!
Just because people are earning a living from something, doesn't necessarily mean they are very good at it.

Theres a lot in that Chester, no mechanics nowadays just fitters, swop one bit for another, give em a cylinder head and ask em to decoke it and grind the valves in and all they want to do is fit you a new cylinder head.
_________________
Proud Father of , 05 ktm 400exc supermoto 2018 honda crf rx supermoto

I hear ya, everyone is after the money, no one wants to work hard for small pay and fixing old things pays less than just fitting the new part and moving on to next car/bike.

I started with push bikes when I was young, probably 10, raced them for a bit, also worked in my dad's repair shop since I was tall enough to reach under the hood.