Fork Feeler gauge

Cheers TB

That would be great. I will PM you my address and if you PM your banking details I will sort out the payment.

Thanks

STM

I will do whatever OBT requires of me :laugh:

Cheers

STM

Disclaimer: I am by no means an expert on dirt bike maintenance. I did ask how to do this job and not only got directions but supplied with the gauges (thanks TB). I thought there may be others with the same question who have not used them before so to all those people, this is for you.

Leaking USD forks are not uncommon as the weight of the oil is constantly bearing down on the seals. Seals should be changed regularly as part of your maintenance regime but not all leaks mean that your seals are shot. Often it is just a bit of grit that is caught between the seals and the fork stanchion that is causing the leak. If you don’t remove this it will not only leak slowly but lead to premature seal wear and can also score your precious inner leg which is something you want to avoid at all cost.
This job can be done with the fork installed but I am going to remove the leg so that I can give everything a good clean without rolling around on the garage floor.
Start with a clean bike and remove front wheel.

Remove any brake or speedo cables running down the fork leg and then loosen all crown bolts. If the fork leg does not slide out easily then lever the crown gently with a flat head and slide it out.

Give the fork leg a good clean and lay on the bench. First thing you have to remove is the dust seal. Roll out the wire o ring

and gently lift the dust seal with a small flat head. Keep a steady hand and work your way around slowly as you do not want to slip and scratch the inner leg. Once this is removed slide it down and out of the way.

Next is the oil seal circlip. Using a small flathead squeeze it toward the leg and it will lift away from the oil seal

Again, be careful to let this make its way gently down the fork to avoid scratching
Now is another chance to give thing a good clean but give the brake cleaner a rest here. You don’t want something that harsh on the oil seal. Just use a moist cotton bud and give it a good reaming.
Now it is time to get the feeler gauge out and get rid of the culprit.

Hold the gauge beside the fork leg and use the hook end as the leading edge. Inset the gauge in a circular motion and progressively sink it deeper into the fork.

Once you are in about an inch the keep rotating and slowly remove the tool as you do. Keep things progressive here as you don’t want to damage the inner lip of the seal.
You can now compress the leg to see if you have stopped the leak. If not try again and if it still leaks then you need seals. At least it is out of your bike and the job is a bit easier. Hopefully though, you have stemmed the flow and the job is done.

Time to reassemble and reinstall. Before refitting the oil seal cir clip and add a bit of lightweight oil around the inner leg. This will help lube the inner leg when you give it a few pumps and help reduce stiction.

Replace circlip and check that it is sitting flush inside the outer and not rubbing on the inner. Replace dust seal, o ring and you are done. Give it a few more pumps on the floor to lube the shaft, clean and you are ready to reinstall into the fork crowns. Make sure you rotate as you tighten these bolts as the will strip if you over torque them. This is the point were you would rather a leaking seal so be careful.
When it comes time to replacing the front wheel you want to make sure you don’t bind the fork. This occurs when the axle is done up with offset lowers and makes the forks work against each other rather than together. To avoid this start by tightening the axle with no weight on the front wheel. Once you have the correct torque put the front wheel on the ground and compress the fork a few times and whilst it has weight on it do up the pinch bolts. You should do this with the bike as upright as possible so that the pinch bolts tighten flush.

Drink more beer

STM