Fork Oil and Should I do Fork Seal Change ??

9 replies to this topic
  • The_Missile

Posted July 12, 2004 - 01:51 AM


Well I managed to change the timing on my bike no problem. But when I look at the manual for the forks.....gadzooks !!! Its about 15 pages worth in the Clymer. I'm not sure I have the courage.

So my forks are leaking. I have done the credit card under the oil seal thing a number of times now and its been 3 yrs since I changed the fork oil, or the seals.... so I guess I'm about due for a service. :thumbsup:

So I'm going to take the forks apart to change the oil. I'm told its easy, so I'll give it a go,
1) how much more of a pain is it to change the seals if I have the fork apart anyway ?
2) do I need the seal driver, and cartridge holder to just change the oil ?
3) is there anything I can seriously &%*& up by doing this myself ?
4) Is there anything I need to NOT forget to do whilst I'm rebeuilding? The loctite thing concerns me as I cant get my hands on loctite here in Switz.....loctite, keskesé ???

I'm as far as having both forks lying on my bench waiting for my attention. I'm toying with the idea of taking the forks in to the shop. Convince me I need to do this myself !!??

All help muchly appreciated !

  • Hamish

Posted July 12, 2004 - 02:08 AM


Cant help you on this one sorry. These days I just rip out the forks or shock and take them to a dirtbike suspension specialist. For the small $$ he charges, it's not worth the hassle. If you cant get loctite any thread locking agent will do just fine.

  • WR450F_RDR

Posted July 12, 2004 - 04:17 AM


Well you can save yourself a lot of money doing it yourself and it is pretty easy.If you are already pulling the forks apart then changing seals and wipers (I recomend both at same time) is easy. You dont need a seal driver, do as search on fork seals there are other ways to install then without spending the money on the tool, I ended up using a heavy duty cardboard tube split in two as my driver, it worked well and was free. As long as you dont scratch or gouge the tubes you cant really do any harm, just be careful with the tools around the tubes. I didnt take apart the lower damper rod so didnt need the special tool for it, I didnt think it necessary at this time. As for loctite, I hear finger nail polish works well .Just take your time, keep everything clean and above all remember how it goes back together :thumbsup:

  • Indy_WR450

Posted July 12, 2004 - 09:14 AM


Replace the bushings, clean the valves, change the fork seals and dust caps once a year. Fork oil change 4 times a year. :thumbsup:

  • JVP

Posted July 13, 2004 - 08:32 AM


Wow! :devil: Change shock oil four times a year? Unlike the motor the shocks are a closed system. The oil should stay clean unless there is a broken seal, then you are going to change the oil anyway. Once a year is fine. That's my opinion. :thumbsup:

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  • tcmII

Posted July 13, 2004 - 05:06 PM


Make sure that you have a thin 17mm open end wrench handy. You'll need it to get the fork cap off of the damping rod. The wrench needs to get between the spring seat and the cap.

Also, I supported my bike with a hydraulic jack, so I could raise and lower the bike to get the rods up after they slid down into the tubes.

  • blireef

Posted July 14, 2004 - 05:54 PM


red line oil is good, so is yamaha stuff.

  • The_Missile

Posted August 16, 2004 - 08:29 PM


Success. It was so easy I thought I was dreaming.

The complexity of the clymer guide is deceiving as there are literally only about 13 parts that need disassembling including the fork tube and slider !

The only tricky bit was using my home made cartridge tool which almost wasn't up to the task.
I think I may spring for the real deal.

Also... I didnt even spill any oil - I had visions of giving my tools an oil bath but it didn't happen. :thumbsup:

Given the cash flow situation at the moment I only cleaned the system and changed the oil and reset the clickers to stock.

Oil was pretty expensive though at about 30 $ a litre. I think we get shafted in Switzerland !

Anyone thinking about changing their oil - go for it. Its sooooo easy. Changing seals is a little trickier, but only because you need to manufacture (easy) or buy (expensive) a special tool, but still very easy mechanically speaking !

  • Brettv

Posted October 17, 2004 - 12:45 AM


hmm, so what about the rear shock, ive got a 99 400, i doubt the oil has ever been changed.. is this bad? am i wrecking something if i leave it?
how hard is it to change the rear shock oil, and or service it? :cry:

  • rush66

Posted October 17, 2004 - 12:46 PM


Your not going to wreck anything by not changing it but like any oil it will break down over time, changing it will restore some plushness. I've service my rear shock and it did function smoother after the oil change. just follow these instructions Shock oil change link make sure to get all the air out of the shock then recharge the nitrogen to 145psi. :cry:


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