Wednesday, February 22, 2017

Dirt Bike Fork/Dust Seal Replacement

*As always, these instructions are general guides to helping you; always check with your service manual for your machine to make sure that you have a clear understanding of the setup. If you are not experienced with installing parts on your machine, Boss Bearing always recommends taking your machine to a mechanic to ensure proper installation. You can buy the partsthrough us, save a few bucks, and take them to your local mechanic to be installed!


*It is important to make sure you clean your machine to prevent any problems going forward with the installation.

*Please be sure to follow the instructions thoroughly! If the steps to replacing any parts on your dirt bike are done improperly, this can lead to parts failure or possible injury.


1. Place the dirt bike on a stand getting the front wheel off the ground. Remove the front wheel and hang caliper so no damage will occur to the brake line hose.

2. It may be necessary to remove the handle bars. Loosen the top cap of the fork (usually 46mm-50mm fork cap wrench will be best to use). It’s best to loosen it while the forks are still on the bike.

3.  Loosen the triple clamp bolts holding the fork legs in place. Remove the forks from the bike.

4.  Remove the top cap and compression adjustment rod and spring. Drain the old fluid from the fork.

5.  Remove the dust seal with a flat screw driver. Then remove the retaining ring clip to allow the fork tube to be disassembled. Separate the fork inner and outer tube by jerking them in opposite direction of each other.

6.  After the fork is separated, you can now remove the bushings, washers, and inner oil seal (keep the parts organized). Clean and inspect all parts for wear and tear. (Replace any parts that are damaged)

7.  Using a seal bullet or, if you don’t have one, use tape on the sharp edges of the fork to prevent the new seal lips from tearing. Slide the new seals, clip, washers, and bushings back on the fork tube in the same pattern they were removed.

8. Reassemble the fork tube and using the proper fork “seal driver” (needed and required), drive the new seal in place. Put the retaining clip back in place, then drive the dust wiper seal.

9. Drip the fork spring into the fork then fill it with the proper amount of appropriate fork oil.

10. Reinstall the compression adjustment tube and the fork cap.

11. Compress the fork leg many times to circulate the fluid.

12. Reinstall the forks back on the bike and reassemble it.

Now you are all set to get back out there and ride again!