changing the fork oil, tips wanted

8 replies to this topic
  • sirthumpalot

Posted July 04, 2001 - 04:10 PM


OK yall, it's about time for my first fork oil change. It would be wonderful if you guys could post your favorite methods and tricks to getting this done right as well as any warnings. This will be my first oil change on a set of inverted forks.


  • bjscheel

Posted July 04, 2001 - 09:19 PM


Get your self an impact gun and vice grips. after taking the spring and guide out take the vice grips with a piece of leather and clamp the dampining rod. Then take the impact gun and whatever size socket your valves are in the end of your forks and while puting pressure on the rod with the vice grips buzz your vales out. Once your valves are out pull the dampning rod out and pump the old fluid out. Clean up any film and reinstall the rod. Once you start the thread on the valves you can tighten them the same as removing them.
Now stand the fork up and pour the oil in a little at a time while pumping up the compresion on your dampining rod. Pull the the rod up and down about 2-8 inchs, more than eight and you will suck air.
Once you have got all the air out and have steady smooth action of the rod fill the the fork to your desired oil height and finish putting the fork together.
Good luck it's not really hard just messy have lots of clean towels.

  • DaveJ

Posted July 04, 2001 - 10:12 PM



In most cases, you don't need to remove the compression tubes to do a simple oil change. However, if you find you have excessive debris in the oil, you may want to fully disassemble the fork for proper clean up.

And you should never hold the compression rod with any such tool. The rod is too fragile. In addition to this, it won't do any good anyways since the rod just spins freely. Either get a compression tube holder or just use an impact gun and a 14mm allen socket.

Other than that, it's just a matter of pulling the springs and pumping the oil out with the fork up-side-down.

On the re-fill, you'll need to remove any air from the compression tubes by working the rod up and down. Add oil as needed. Then before setting fork oil height, slide the outer fork tube all the way up to remove the oil between the two tubes.

Lastly, if you do pull your forks apart, almost always never use solvent to clean them. It's usually best to just wipe things off or down.

And make sure to align the forks when installing the axle. So many people fail to do this and it makes a big difference in handling and with the life of the fork.

Best of luck.

  • sirthumpalot

Posted July 05, 2001 - 03:03 AM


When you say line the forks up with the front axel, is this to say that they do not rotate freely in the upper tubes?

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  • Guest_Guest_*

Posted December 21, 2001 - 06:16 PM


Here's my comments based on my recent experience changing the fork oil for the first time on my 2001 426.

(1) I bought a 14 mm hex socket for the compression valve at the botom of the fork from Snap-on online for about $20-$30. Could't find one anywhere local. I also bought a 14 mm allen wrench from Napa online for about $8. I wanted the socket so I could use my torque wrench when putting them back together.

(2) I bought a cartridge holding tool from Scotts for about $35. You need it if you don't have air or want to use the proper torque when putting things back together. You can also make one if you want - see motoman393's web site.

(3) I bought the Motion Pro fork oil height tool (basically a syringe and tubing for $30) not because I didn't know how to fashion something that COULD work but because I wanted something that WOULD work right away.

(4) I followed the instructions in the manual for removing the forks, etc but did NOT split the inner and outer tubes. I just took the springs out, removed the valve/cartridge, dumped the oil from the forks and worked the damper rod from the cartridge up and down a bit to remove the oil from there. You will be able to tell when there is no more oil in the cartride.

(5) I inspected the compression valve and found really no sludge or crud so I wiped things down, and put the cartridge and compression valve back in.

(6) I followed the instructions to refill the oil, they are pretty clear. I used Enzo "01" oil and set the oil height to 115 mm (I am 185 lbs and a beginner/novice but ride fairly aggressively, I can "slap" landings and over/under jump things very nicely - LOL).

After all of that I put things back together as the manual says.

I rode the last two days on my *new* forks and I am very happy with the results.

One last thing - I measured out app. 14 cc for 10 mm in oil height. So if I decide to adjust the height now, I can add 14 cc through the air bleed screw to get to 105mm height, etc. I make no claim that my measurements are precise. You should do it yourself to be certain...

I hope this helps others who are new to this ... !

Steve T

  • sirthumpalot

Posted December 21, 2001 - 07:06 PM


Thanks for the info! I finally did the change myself a few weeks ago. I didn't take the forks totally apart (just removed the spring and then pumped out the oil from there) so I'm very glad to hear that you didn't have any real sludge in there yet. Does that oil feel the same as the original oil to you? Also how much did you pay per litre?

  • Guest_Guest_*

Posted December 21, 2001 - 07:40 PM


Yes - the Enzo 01 was very similar to the OEM juice. I found it on my local dealer's shelf for about $15 per quart (0.946 liter).

BTW I had about 30 hours on the bike...

Steve T

[ December 21, 2001: Message edited by: YZF426ER ]

  • dan_Rekito

Posted December 24, 2001 - 11:12 AM


Her's a cool trick I use . after filling oil etc. I use a squirter off a windex bottle with a piece of tape [measured up the squirter tube] for oil height. Just put the squirter in the fork up to the piece of tape and squirt out the excess, It will be exact on both forks! --- The dirt must fly!!--- :)

  • motoman393

Posted December 24, 2001 - 01:15 PM


I use the same method dan Rekito uses...and it works great!

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