HELP! Replacing seal on bottom rear shock
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    momuzik
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    HELP! Replacing seal on bottom rear shock

    by momuzik » Sun Nov 30, 2014 1:43 pm

    I picked up a pro action rear shock for my crf250x but it leaks from the bottom seal (see pic) and plan on replacing the seal myself and needed some advice since Im new to these kind of shocks.

    To replace the seal do I remove the Phillips screw holding the bottom shock bracket to the rod, then remove the rebound valve?

    And after I replace with new seal, do I fill the oil where the rebound valve is then replace the valve and tighten, and how much oil? brand/type?

    Do I need to release the nitrogen pressure before any disassembly prior to replacing the bottom seal?

    Any help would be gravely appreciated, thanks
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    JimDirt
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    by JimDirt » Sun Nov 30, 2014 4:17 pm

    Do you have a Honda Service Manual ?? , i would recommend getting one before attempting to replace the seal , as you will have to completely disassemble the shock to remove the seal (not a Clymer Manual , a Factory Service Manual
    http://www.crfsonly.com/catalog/product ... ts_id/3226

    That shock is basically a stock Honda shock that has been re-valved and re-worked so the function and servicing is the same as stock

    You will also need to bleed off the Nitrogen before attempting dis-assembly , and find someone that can re-charge it for you

    These videos will give you a idea of what is needed to service the shock , but again , i recommend getting the manual first , once you have the manual with detailed pictures and info , its not that hard , but dont blindly tear into it or your asking for trouble , i can walk you thru any questions you have , as things need to be measured and assembled in the correct order so if you get stuck with something in the manual , i can guide you thru it , and doing it correctly is a necessity or the shock can come apart while riding if you dont do things right

    Its easy once you do it a time or 2 , but dont go blindly into it , because when charged , its under a lot of pressure

    http://www.racetech.com/page/id/138
    2020 CRF450R
    2006 CRF450X
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    Weiser , Idaho
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    momuzik
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    by momuzik » Sun Nov 30, 2014 5:43 pm

    ok thanks JimDirt, sounds like its more of a hassle than its worth being that I dont have nitrogen or the specialty tools that would be needed, and then be effed should I happen to tear into it and find out the hard way

    so for now maybe Ill send it to Pro Action to replace the seal and just have them service it

    normally Im an awesome mechanic, former aircraft, but even I know unless I have special tools that would prob be needed to tear the internals apart, Im screwed...lol

    thanks Jim
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    JimDirt
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    by JimDirt » Sun Nov 30, 2014 6:17 pm

    You only need a few special tools , and if you plan on doing your own work its worth getting them , i service and re-valve all my own stuff , its not that hard once you figure it out , just dont go into it blindly , thats why i posted the video's , it gives you a idea of what your up against , like i said , once you do it a time or 2 its easy , but things need to be done right , that is why the manual is so important

    I dont have all the trick tools like bullets , etc , i get by with plastic bags and ground down wrenches , i do have a Nitrogen bottle , which will set you back about $250 with gauges , and a clamp that attaches to my bench vice to hold the forks and shock when i am working on them , and a seal driver , thats about it for specialty tools and i do fine
    2020 CRF450R
    2006 CRF450X
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    Weiser , Idaho
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    momuzik
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    by momuzik » Sun Nov 30, 2014 10:38 pm

    ok thanks Jim for all the help, it would only be a onetime repair for me so yeah Ill have it done professionally instead of investing in tools and a nitrogen setup, perhaps one day I may service them in the future but who knows. Thanks so much for all your tips and sound advice, much appreciated
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    JimDirt
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    by JimDirt » Mon Dec 01, 2014 7:03 am

    No problem , glad to help , any more questions , just ask ! ;)
    2020 CRF450R
    2006 CRF450X
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    Weiser , Idaho
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    momuzik
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    by momuzik » Wed Dec 10, 2014 1:56 pm

    hi jim I purchased the seal for the rear shock and getting ready to dissassemble next week to replace the shock seal, is 5-wt correct and do you know the capacity/amount needed and how to bleed?? thanks Jim
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    JimDirt
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    by JimDirt » Wed Dec 10, 2014 5:29 pm

    Yes you can use 5wt fork oil , though i prefer 3wt shock oil (plusher feel) I use Maxima

    What you want to do is first (after removing the shock of course) , is to remove the spring by loosening the lock collar , then spinning the main collar up onto the threads so there is no tension on the spring and you can move the spring up and down loosely , then down at the bottom there is the flat plate that the spring sits on , it should lift up , if it does not move readily then just lightly tap with a rubber mallet till it comes loose , tap opposite sides so it lifts evenly , you will then see a large C-Clip , take a small pointed punch or a small flat screwdriver and remove the C-Clip , then slide the flat collar off the shock and remove the spring

    Now remove the cap from the air fitting on the bladder tank (the part that sits off to the side of the main shock body where your compression setting is) , now release the air (Nitrogen) , it will just go psssst , it wont be a lot of volume , just a small psssst of pressure

    Now take the shock and turn it upside down , where the body meets the shaft there is a aluminum cover , it has 2 holes in it on opposite sides , take a small pointed punch and lightly tap into the hole at a angle so your pointing towards the shaft
    (like this)
    Image

    (I will post more after i eat dinner , since this will take a while)
    Last edited by JimDirt on Wed Dec 10, 2014 7:24 pm, edited 4 times in total.
    2020 CRF450R
    2006 CRF450X
    Image
    Weiser , Idaho
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    momuzik
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    by momuzik » Wed Dec 10, 2014 5:48 pm

    ok thank you Jim, enjoy your dinner :D
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    JimDirt
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    by JimDirt » Wed Dec 10, 2014 7:25 pm

    OK I'm back ... sort of !

    I will edit as i go (when i stop for the evening or meal breaks) , but i will try to keep it all in a few posts so you can follow it easier

    I make pretty detailed tech posts ,(if you have read any of my other suspension help topics you will have noticed this) , i am far from a expert , but i dont mind sharing the knowledge i have acquired , i dont know everything , but as i posted before , if your stuck on something , just ask and i will usually be able to talk you thru it , or review those videos i posted links to , they are very informative

    I will upload reference pics like the one above as i go , so you can use them for reference , they are from my 450X Service Manual , but everything is exactly the same, , and i only have a 250X Owners Manual so it does not show the shock breakdown , just the forks (that is why i said buy a Factory Honda Service Manual for it , it will show everything) , i have Service Manuals in PDF format for a quite few bikes like various Honda's ,Yamaha's,KTM's,Suzuki's,Kawasaki's, , just not the 250X (i have one for the 250R) , but all the Honda shocks are exactly the same so what i show you will look just like yours

    I have to do some work around the house during the day (remodeling , so , drywall ,texturing,painting, etc), so i might not come back to post the rest till tomorrow evening after i post this tonight , but i will have everything posted before your ready to tear into it, so you have a chance to familiarize yourself with everything you will be doing beforehand
    2020 CRF450R
    2006 CRF450X
    Image
    Weiser , Idaho
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    momuzik
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    by momuzik » Wed Dec 10, 2014 8:33 pm

    thank you so very much Jim for taking the time to share knowledge, very very much appreciated.

    to save you time the only portion I will need would be after I replace the seal, in other words "REASSEMBLY" as I wont want to miss any details such as: amount of oil, bleeding, etc.

    once completed I will find a place that can recharge the nitrogen

    everything you share with me is invaluable and very very much appreciated, thank you Jim for taking the time to share...Im sure this will be valuable for other CRF members as well and much thanks again
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    JimDirt
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    by JimDirt » Sat Dec 13, 2014 5:33 pm

    Sorry i have not been back on much , i have been battling migraines , because of my fused neck , and from looking up all day at the ceiling doing drywall mud sanding , so i will get with finishing my post tomorrow evening , for you , ....... question , have you already , or are you aware of the procedure of cutting the damper rod end and proper removal of the nut so you can remove the valving to get to the seal ?? , if its not done correctly (it shows how in the Factory Service Manual)you can destroy the damper rod

    So i can start from dis-assembly of the stack assembly , if you like (which is where i was headed next in my original post anyway)

    If not i will just do the re-assembly as you asked
    2020 CRF450R
    2006 CRF450X
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    Weiser , Idaho
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    momuzik
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    by momuzik » Sun Dec 14, 2014 4:33 pm

    hi jim no Im not familiar with cutting the damper rod procedure, I think it would be better for me not to do this and taking a chance of ruining it, lets go with the reassembly portion if thats cool

    take your time my friend and hope you get better soon, thanks so much for your assistance!
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    JimDirt
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    by JimDirt » Mon Dec 15, 2014 3:09 pm

    The only issue is........Cutting the area to remove the nut is part of the procedure to get to the seal to remove it , basically the entire internals have to be dis-assembled to get to the seal to remove it before you worry about re-assembly , including the valving , its not that you should not be able to do it , but just it has to be done correctly , if you feel you can do what i am posting here , you can replace the seal which is located in the Rod Guide Case which is one of the last components to come off the rod (shown in the last pic)

    ....... THEN you can worry about re-assembly procedures , if you feel you can do it (by basically doing what is shown in the pics) then i will go ahead and do the re-assembly write up , not trying to discourage you , just making sure you are aware what your getting into , its not rocket science , but you cant just tear it apart and slap it back together either ... but i will be glad to TRY to walk you thru the procedure as detailed as possible , if you think you can handle it , if your really not sure about it after looking over these pics , then definitely send it to a qualified shop (any reputable suspension shop (Ken can do it for that matter)
    Image
    Image
    Image
    Last edited by JimDirt on Mon Dec 15, 2014 5:18 pm, edited 1 time in total.
    2020 CRF450R
    2006 CRF450X
    Image
    Weiser , Idaho
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    momuzik
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    by momuzik » Mon Dec 15, 2014 3:45 pm

    ok thanks Jim Im going to tear into it sometime this week and let you know how it goes, thanks so much for sending these pics/instructions, really helps alot :)

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