replacing fork seals

9 replies to this topic
  • frankycottonrow

Posted May 21, 2008 - 12:52 PM


Is there a how to somewhere on the site? I have searched and had little luck. What tools are neccesary.


  • grayracer513

Posted May 21, 2008 - 01:11 PM


The manual works fairly well. You can approach the repair in two different ways; a full break down and cleaning of both chambers, or a minimal tear down just to replace the seals and get out. Neither is very difficult. Have you looked through the manual yet?

  • Stepdaddy

Posted May 21, 2008 - 01:41 PM


Id also like to know what tools are required. Im sick of payin the same guy 150+ parts to do my forks.

I guess I should go over the manuel and see if any info is given :thumbsup:

  • grayracer513

Posted May 21, 2008 - 02:52 PM


Tools you will need to do an '06 or later are:

Cap Wrench/Rod Holder combo

Compression Valve Wrench

Seal Driver

There is one other tool you will need that isn't specifically called out in the manual, but you might not have one if you don't work around American cars much, and that's a 15mm open end wrench for the damper rod lock nut.

Let's go over the process. The manual starts on page 5-28 by reminding you to loosen the caps (actually the end of the damper assembly) before removing the forks. It is advisable to loosen the upper pinch bolts before doing this, just to ease things a little, and if you have raised your forks, you may have to slip them down a little and snug up the lower clamp to have enough room to get the wrench under the bars.

Remove the fork, unscrew the caps, dump the oil, and continue on page 5-29. If you do not have a rod holder tool like the one on page 5-29, use a pair of pliers, not to grab and hold the rod (you don't want to scar it), but to allow the nut to sit on the sides of the jaws. Compress the lower fork leg until the damper rod extends far enough out of the bottom to engage the tool. (The axle placed in the lower fork leg makes this easier) If using pliers, gently close them around the rod, and let the fork back up until the lock nut bears on the sides of the jaws and stays there. You'll see what I mean.

Once the adjuster is off, remove the damper cartridge and set it aside.

Proceed to "Inner Tube" on 5-29. When the clip is disengaged, compress the main tubes part way and extend them sharply against the internal stop to drive the seal up and out. It makes a noise. Don't worry about it. Carefully remove the bushing from the end of the tube, and slip the rest of the parts off, laying them out in order, right side up.

Unless changing the inner cartridge oil, proceed to page 5-36. See the note in step 15. Use a sheet of plastic, like a grocery bag, to cover the sharp edges of the bushing groove to avoid cutting the seal lip. Note also the application of some grease between the oil seal and dust seal in step 21.

In assembling the damper back in to the fork, do two things first: Check for a minimum of 19mm of rod extending past the lock nut, and be sure to back the rebound clicker all the way out.

Put a shop towel or a clean flat board on the floor and stand the cartridge and spring on it, top down. Lower the outer tube assembly over the damper/spring. Slide the axle into the axle lug on the lower fork tube so you can use it as a handle to compress the fork spring.

Now, run the adjuster down until it stops. It should be free enough to be run all the way down by your fingers. Once you feel it come to a stop, you check the gap.

Here is what is significant about that gap. If there is no gap, that means the lock nut stopped the adjuster from bottoming out on the rod. If you verified that you had the 19mm+ of exposed thread to start with, and the gap is too big, that means the adjuster is not all the way down on the rod.

Once you have the adjuster all the way on, then tighten it (step 29) to 21 ft/lb.

If you decide to change the oil in the dampers, follow the instructions from page 5-30 to drain them, then move on to 5-33. The filling instructions have a couple of points where they are unclear. The way it works is that the rod should be fully extended, then the cartridge filled 7 ounces of oil. Then, pump the rod through 2/3 of its full stroke slowly several times to force air out of the valving give the unit plenty of time for all of the bubbles to rise to the top, and don't churn it up.

Now, fill the unit to within 5.5" (140mm) of the top. Back the compression clicker all the way out. Take the cartridge in one hand, and push the rod against the floor to compress it all but the last half inch. Be sure the lock nut is on the rod. Hold the cartridge with a cloth covering the two holes near the top, as oil will be exhausted here as the cartridge bleeds. Now start the compression damper assembly into the cartridge (Step 8, Page 5-34). Pick the cartridge up off of the floor and slowly push the damper into the cartridge, allowing the rod to extend as you do. If you find that you cannot push it far enough to engage the threads, push up on the rod about a half inch to an inch to exhaust a small amount of oil. Then push down and engage the threads. Use the valve wrench to tighten the valve in the cartridge.

Now hold the cartridge at about a 45 degree angle with one of the holes facing up and compress the rod FULLY. Expect oil to be exhausted. Let the rod extend on it's own. It should nearly or just reach the end of its travel on its own, but if it extends clear to the end and still has pressure on it, you need to cycle it again. If you have to pull the rod more than the last 14mm or so, remove the valve, add a little oil, and try again.

It may sound a little daunting, but once you've done it, you'll wonder why you paid so much to have someone else do it. The first time is a little messy, though. :thumbsup:

  • yzf450jack

Posted May 21, 2008 - 09:28 PM


Is there a how to somewhere on the site? I have searched and had little luck. What tools are neccesary.


Let me know what you need t0 know:worthy: I wIlL get yall i no leaky:bonk:

Visit the ThumperTalk Store for the lowest prices on motorcycle / ATV parts and accessories - Guaranteed
  • Stepdaddy

Posted May 22, 2008 - 01:32 PM


Thanks the the help man, Ill be purchasing the tools needed shorty so i can "save" money :thumbsup:

  • steve_97060

Posted May 22, 2008 - 04:39 PM


This tool looks a little more affordable than the MP.. also has the other needed parts/supplies...


props to WIZ636 for showing me this link... :thumbsup:

  • grayracer513

Posted May 22, 2008 - 05:03 PM


That is a good deal, if the tool quality is good. Note that the compression valve removal tool appears to be included with the wrench.

The Tusk seal driver looks identical for $20 less than MP, also.

  • yzfjbw323

Posted May 22, 2008 - 06:52 PM


Check these out

  • frankycottonrow

Posted May 23, 2008 - 12:22 PM


thanks for all the help again guys

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