YZ400 Fork Seal Change

I'm in need of a "good" step-by-step for fork seal change and oil replacement. Just bought a '99 a while back and have a leaking front left. I did the 35mm film trick and it worked for a while but it still was bottoming.

yeah i was wondering how to change the seal myself. my 400 left fork seal is leaking oil.

If you have the manual it is pretty basic. I just did the seals on my wr and it was easy. If you don't have the manual I would suggest getting it before stating this process.

The short version. Remove forks from the triple clamp, take the caps off and remove the springs. Dump the oil out. Pump the dampner rod up and down many times to remove all the oil. pull the dust cover back, then fully compress the shock and pull it back quickly a few times to dislodge the old seal. Install new seal( i took mine to a mechaninc and had him press the seal in, didn't cost me anything) then add oil to appropriate level, pump the rod a few times to evenly disperse oil, add more if necesssary, put every thing back together.

It is easy, but there are some important steps that i didn't explain that are explained very well in the manual. Beg, borrow or steal to get a manual before starting. It has all the torque settings and other helpful info.

Get the manual. OH and BTW get the manual.

SlowJoe and Hmrland - Where are you guys located? I'm in Huntington Beach and would be happy to walk you guys through the process if you would like to drop by and learn. I have all the tools you'd need.

SXP knows his Yami forks!!!!

He helped (actually, did most of the work) on my YZ426 forks and shock. We swapped out springs, changed seals/bushings and replaced fluid in the forks. It didnt seem too tough but it was nice watching him do it and I know I can do it in the future. Plus he has all the tools that would otherwise have you rip your hair out.

Thanks again SXP!


Thanks. I'll definitely take you up on the offer. I'm down the road from you in Lake Forest. I'll PM you to see what your schedule is like the next couple of weeks. :cry:

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