Removing front fork metal caps


XS400 New Member
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Nottingham, NH, USA
I want to replace the fork oil in my 1981 XS400SH (4R4). When I removed the rubber caps on top I, and my motorcycle maintenance mentor, were surprised at what we saw.

We'd expected there to be a slot that would allow us to unscrew the inner metal cap.

OK, so then we looked at the manual, and we see that you need to press the metal cap down so you can remove the circlip. Depressing the cap seems to require a lot of pressure, and we didn't want to break anything, so we're now doing add'l research.

Do we have this right? Is this the way to do this? From reading around the net it seems that this comes down to the elegant application of brute force. Any tricks on how best to do this?

Other thoughts.


// Jack

PS. Here's a pic of the bike.

yep brute force is needed preferably with another person (I use the wife) get a little terminal driver to flick out the circlip. (try to see where it goes!)

watch out the cap may stay in for a little bit then spring out suddenly
If you only want to replace the oil and not the sealing, there's an other version:

Unscrew the little srcew on the bottom side (Part 26), pump the old oil out.

Then rotate, so the upper side is down, and fill the new oil in the screw hole with an medical injection.

Then put in the srcew, rotate and pump three or four times. Final! :wink2:

Hi Jack,

This is what I do: put a small diametre socket bit (10mm) on top of the cap, lay a big flat end screwdriver across the bit and stick the flat end of the screw driver under a fixed part of the triple tree. Push the handle down and lever the circlip out with a small screwdriver. Assemble in reverse order.

Kind regards,

Thanks. That's an interesting ideas. Problem is, the fork is still on the bike, so flipping the whole thing would probably make for an even bigger challenge. :)


That's sounds like an interesting procedure. I'm gonna give it a try.

Thanks all.

// Jack
Good luck Jack,

Also try to relieve the spring tension by putting the bike on its centre stand and keeping the front wheel off the ground (jam a block of wood under the frame).
And I would definitely second Drewpy's comment about needing two people, I did mine on the driveway in the semi-dark on my own. Putting the circlip back in whilst holding down the spring is, er, challenging shall we say. Air was blue by the time I'd finished.
I made a tool out of an old automotive disc brake piston compressor. It has a thin crescent shaped metal piece shaped like a brake pad with a threaded rod through it. One end of the rod has a rotatable metal disc about the size of a quarter and the other end has a plastic knob to make it easy to turn. I ground down the metal disc so that it fits inside the top of the fork tube with enough room to clear the internal circlip. I then slipped the crescent shaped piece between the tach or speedometer cup and the underside of the handlebar mount and threaded it down until it depressed the fork tube cap far enough to get the circlip out. Backing it out slowly, the cap can be removed in a controlled fashion to avoid having to chase it across the garage.


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This is an old thread, but since it under tech I will post my solution. There is more than one way to skin a cat.

To compress the spring stop to remove the clip I used an old windshield support bracket. It is a perfect fit. I have seen these at swap meets for a few bucks.

Most of the folks here are mechanically inclined, so it needs little explaining. For those who are not, make sure you keep pressure on the rod with one hand when loosening the nut and then slowly release the rod with a rag wrapped around the top of the fork tube to catch the stop.

The manual calls for changing the fluid @24 months, this bike was a little overdue, it was black.

Hope this helps.


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I had some trouble with this as well some time ago, I was able to push down the spring stop while pushing a giant screwdriver down on it, and then using a tiny flat screwdriver to flip out the circlip. First try I spent about 30 minutes cursing at it (with a friend who also couldn't get the clip out) and then gave up. Second try a few days later it was out in 30 seconds. No need for special tools, you just need to get the hang of it :thumbsup:
This is an old thread but, I compressed the top,took the clip out...and the top/spring does not come out :wtf:....
Any ideas?
They can get rusty and stiff. There's also an o-ring in there that likes to be difficult.

Mine came out with some wd 40 and wiggling.
reminds me of the time i had to get the cap lathed out bit by bit. the engineers said that the operative compressed the fork then took a bit out each time.
he gave it a good whack on the bench and looked in the fork leg for the spring which was strangely missing. Wierd he thought, then it hit him right on the head.

the spring must have shot up and being an old factory had very high ceilings. the spring must have got to 30ft before landing on the unfortunate lad's head.
Try using a three legged gear puller to depress the fork cap's, then the circlips can be extracted at leasure! Then slowly unwind the puller to release the caps under the pressure of the fork springs, sliding the end caps out! Reverse the procedure, to rebuild the forks after refilling, with new oil!
Loosening the upper yolk/tree pinch bolt first can make a difference. I fought to get the caps to depress until I loosened the pinch bolt. Then the cap moved freely. I wouldn't have expected it to make any difference, but it did... :shrug: