So you have removed the forks, disassembled them, assessed and cleaned the components and now you want to put them back together. If you paid attention when you took them apart you should be pretty familiar with this process as it’s basically a reversal of the previous steps.

You should have the above components as well as the chrome fork stanchions.
Install the bushing onto the chrome fork stanchion, sliding it down from the top:

Then the back up ring:

Next comes the fork seal. We are using ARX seals today:

If you are in doubt as to which end goes up, the end with the writing on it faces upwards.

Wrap electrical tape around the top of the fork tube to stop the edge from damaging the inner seal lip, and make sure that the fork tube is perfectly smooth with no rough spots, rust areas or anything else which might catch the fork seal as it slides down. Lubricate the inside of the fork seal with fork oil:

You should now have a chrome stanchion that looks like this on the bottom end:

Insert it into the fork lower. The stanchion will go in easily but the fork seal will sit at the top:

Get your old fork seal and slide it down to sit on top of the new one, then get a length of 40mm PVC pipe that’s about 2′ long and slide it down to sit on top of the old fork seal:

The point of all of this is to give us a surface that we don’t mind damaging when we press the old seal in. Use a rubber mallet or similar to bang on the top of the PVC and drive in the new fork seal, making sure not to let the PVC move out to the aluminium stanchion and to bang it in evenly. If you’re using a rubber mallet that’s likely to shed bits of itself into your fork put something over the top like an aerosol can cap to prevent junk from getting into your suspension:

Once the oil seal has seated you should be able to lift the chrome stanchion slightly and the old fork seal will lift with it – slide it off as it’s now no longer needed.

Grab the snap ring you cleaned up and install it into it’s recess above the fork seal:

Grab a new dust seal:

It’s a basic press fit into the fork above the snap ring:

Now we install things into the fork. The oil lock piece is probably still inside the fork lower – it was on ours so we can’t show inserting that first – so now put the rebound spring on the damper rod and insert that into the fork:

Drop the spring in – if yours has one end where the turns are closer:

Then drop the washer in:


Then the spacer:


Now install the fork cap – it doesn’t have to be tight at this point:

This will put pressure on the rod so we can install and torque the bolt at the bottom of the forks. Grab the bolt, use a new copper washer:

Use a 6mm hex long socket to install it – torque it to between 0.5-2.0kg/m. We picked something about 2/3 of the way up that scale, which worked out to be ~11ft/lb.


If you loosened the drain bolt on the side of the fork use a new copper washer and reinstall those. Now if you want to use the technique of measuring how far down the oil is to know when to stop putting it in then remove the fork cap bolt/spring/spacer/washer, fully compress the fork and pour oil in until the level is however many mm below the top as specified below. Otherwise, remove the fork cap and pour in the volume specified below:
Model | Fork Oil Volume | Distance from top of stanchion to top of oil, fork fully down |
---|---|---|
MC14 | 290cc ±2.5cc | 114mm |
MC17 (CBR250RH) | 302cc &plusm;2.5cc | 100mm |
MC19 (CBR250RJ) | 362cc &plusm;2.5cc | 95mm &plusm;6mm |
MC22 (CBR250RR L) | 383cc &plusm;2.5cc | 83mm |
The manual calls for automatic transmission fluid to be used – this is supposedly the equivalent of about 10wt fork oil (eBay AU, Amazon). Given that modern fork oil is freely available and is specially formulated for forks – unlike automatic transmission fluid – we would suggest using that in it’s place.
Reassemble the complete fork – you don’t need to tighten the fork cap all the way just yet. Now you’re ready to do the reinstallation process.
Thanks a lot for this. I am about to replace the seals in my forks and this will be very useful in reassembling them. My fork tubes have little spots of damage, probably from stones hitting them, and also some rust from the triple clamp. I found that aluminium polish, rubbed with my fingertip, was a good way to remove rust and roughness without ruining the shine of the undamaged surface. I think that Meguiar’s Ultimate Compound (for polishing cars) or similar would probably work well too.
Welcome – and good tip with the polish!