640 adventure fork seals changed by noob?

Discussion in 'Thumpers' started by SFmax, Mar 27, 2007.

  1. SFmax

    SFmax Guest

    Here is the scenario.

    Just put about 1500 miles on my newish 03 adventure that I just bought. Unfortunately the leftside fork seal is shot. I was wondering if replacing the fork seals could qualify as a saturday job. Or if its more like a Saturday/Sunday job? It would be in my friends garage who I'd have to bribe with a case of beer.

    In simplified form:

    Is this a two man job or can my buddy drink while I work?
    Is this doable for a first timer on a Saturday?
    Would I be crazy to try and change the oil as well?

    Am I better of paying the guy at Scuderia to do it?
    (the reason I ask is I will be going out of town and can't afford to have the thing laying in pieces in my friends garage all weekend.)
  2. cedric

    cedric Been here awhile

    Nov 7, 2006
    There is no way to change the seals without changing the oil. Well I guess you could pour the old oil back in, but that kinda be like drinking your own piss!

    It's not a really hard job to do, but I wouldn't recommend it unless you are already comfortable working on most other parts of your bike. It can certainly be done in one afternoon. Make sure you have a service manual to show you the steps needed. Read it carefully before you begin, and if you think you can handle it, go for it. You will need to buy/make/jerry rig a special seal driving tool to seat the seals in the tubes.

    I need to do this on my YZ very soon. I've done this task about 5 times before, but I still need to be very careful while doing it.

    As an alternative, you can pop off the dust seals, and work a thin film up underneath the oil seals and wiggle it all around. Often times this will remove some grit and keep your forks from leaking for a while.

    Good luck!
  3. ChrisC

    ChrisC Amal sex?

    Feb 25, 2003
    Prescott, Arizona USA Earth
  4. cevquit

    cevquit maphead

    Jul 7, 2006
    At the foot of the mighty Sierra Nevada
    If you dont have the tools you are much better off having someone who knows what they are doing do it.
    On a side note, the front axle has a floating right side, that is that the axle slides freely through the right side while the left side threads to a stop to tighten. There is no "dead length" position for the right leg, it doesnt tighten against the hub or bearing spacer although the axle does tighten against the bearings.
    When my buddy got his 03 sxc the first thing he did was get a set of motard wheels, after changing them a couple of times and a few rides he got a seal leak. Just a little weeping not much, it bugged him so he got them replaced by a qualified suspension shop. Rode it a few times, couple more wheel changes and ,voila, they seep again. takes it back to the shop that did them and they tell him "well KTM's are known for seepy seals". I've been involved with suspension enough to know that they shouldn't have gone bad that soon, maybe a bad seal,it happens.When he changed front tire the next time I noticed that when he loosend the pinch bolts on the right side the fork sprung out a few mm. Then it dawned on me the forks were compressed towards each other and not running parrallel, causing the fork seals to leak.
    So, tighten the axle first then the left side pinch bolts, give the right fork leg a little jiggle to let it "seat" then tighten the right side pinch bolts.
    Since we found the error in his method of mounting and corrected it, there has been no weepage from the seals in 6,000 miles.
    So, if anyone has chronically seeping fork seals on there WP forks look closely at how you mount your front wheel.
    airgord likes this.
  5. Surly

    Surly surly adventurer

    Mar 17, 2003
    Salem, OR
    Nice tip maphead! Thanks

    I went the seal saver, grease, neoprene boot route
    Will check the axle for sure
  6. Luke

    Luke GPoET&P

    Aug 25, 2004
    Beaverton, OR

    +1 all around. The plastic under the seal worked for me, but not for the last person I reccomended it to.

    If you had done it before, it would be a short afternoon job, but since you haven't I'd call it a long afternoon job.

    In addition to the usual sockets, you will need a seal driver tool, this manual, a 24mm wrench or socket (A big adjustable works too) a low profile 22mm open end wrench and 2 quarts of 5wt fork oil. edit.... and a ruler and a piece of tubing+syringe or mityvac for setting the oil level.

    The manual covers a complete tear-down and re-assembly. The bike manuals don't have this kind of detail. You won't be doing it all, but I'd recommend reading it beforehand so you know what you're getting into.

    I'm not too far away, so let me know if you want help. I'll be riding this Sat. though.
  7. Loadedagain

    Loadedagain making chips

    Jan 1, 2003
    West Vancouver, BC
    lc4 forks is fun.... get a manual and follow wp instructions and you'll be fine.

    be happy you didn't fuck up a tube like i did... that was some shitload of dickin around. :D


  8. bmwktmbill

    bmwktmbill Traveler

    Jul 16, 2005
    Just did my seals.
    The manual called for tools I did not have.
    Use clear packaging tape around the end of the fork tubes to protect the seals when you slip them on the tubes.
    Get the order right the first time and use your fingers to start them. Lube with fork oil. that helps.
    For a seal driver I used a piece of radiator hose I slit long ways and slipped over the tube.
    Tht worked great for pushing the seals into legs.
    I used red grease between the dust seal and the fork seal.
    Some swear it helps.
    Back all adjusters to zero for reassembly.
    Recent thread on that one.

    On the axle problem I had that too and it caused me a leak. Pull the axle out and clean it with a scotchbrite pad or somesuch and get in the axle tunnel too on the fork leg. Clean clean clean.
    Follow the owners manual for mounting the front wheel.
    What a difference.
    No stiction.

  9. Zerodog

    Zerodog Long timer

    Jun 9, 2006
    SLC, UT
    Before you worry about it too much do the film strip thing to try to clean the seal. Also put some heavy grease under the dust wiper. This usually fixes a seal unless it is totally shot.

    Fory changing seals you will need a seal driver too. You can make one or buy one. Or you can get synergy seals. They come with a little plastic strip and you put them in with your fingers. They are more expensive but I guess that is the trade off of not buying a tool you will rarely use. Loosen your basevalves before you take the forks off. An o ring seals it so as long as you just loosen them you won't puke oil everywhere. Having your bike straped down a bit helps this. It keeps the cartride from spinning. Do the same for the final torque down them too.

    Don't buy the MSR seal kit. You will be doing your fork seals again in a short while. Don't ask how I know.........
  10. Zerodog

    Zerodog Long timer

    Jun 9, 2006
    SLC, UT
    Good tip on the seal driver Bill.
  11. Surlyguy

    Surlyguy Guest

    You MADE a tube :eek1

    I have an 18" brand new rear wheel, I'm going to send it to you to shrink to a 17" :wink:

  12. Dotbond

    Dotbond Africa, Africa

    Jun 18, 2006
    Dunedin. New Zealand
    Alright guys, just pulled my left fork apart because it's leaking. The 4357 model. Noticed a nick in the fork leg which I cleaned up with 1200 grit W&D sandpaper. I have looked at the seal and there are indentations in the seal where it was sliding over the nickl so I have to get a new seal.
    Now the big question is, which way does the seal go? i.e. which way is up, as I may have forgotten? :huh
  13. Zerodog

    Zerodog Long timer

    Jun 9, 2006
    SLC, UT
    The smoother side goes out. It is also the one with the writing on it. Grease the inside and outside of the seal when installing. Also use some plastic wrap from the kitchen or packing tape over the end of the fork tube when installing the seal. This will protect it from the end of the tube and more importantly the super sharp bushing groove.:D
  14. gunnerbuck

    gunnerbuck Island Hopper

    Nov 19, 2005
    N.V.I, B.C.
    A nick in the fork tube can be filled with JB weld and lightly sanded level.... It will hold for a long time...
    airgord likes this.