DIY Joplin Top Seal Head removal / fitting tool

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  • DIY Joplin Top Seal Head removal / fitting tool
  • #Edit – This wont mean anything to you unless you’ve ever tried to fix a Joplin.

    I dont know if this will in anyway help anyone but my google searches were futile and seemed to require a special tool. Basically these are DIY instructions to remove / replace the valve assembly in the head / top of Joplin.

    After some bodgetastic removal techniques involving BBQ skewers (if I couldnt diy fix this it was for the bin) I realised there was no way it was going to get refitted without some sort of proper tool.

    The tool is the one mentioned here in steps 11 and 12 (and later reassembly):

    Anyway the holes in the metal seal head assembly are exactly 16mm apart – centre to centre. Hole diameter is a smidge less that the wire in a cheap clothers hanger wire and taper slightly (I have no way of measuring exactly).

    With that in mind I found an old one of these flat wood drill bits in the tool box:

    So I got the angle grinder and file out, and made of of these. Not neat but works perfectly and solved my problem. Note that the deep V is needed to clear the seal rubber in the middle of the head.

    My Joplin was seeping oil from the very top (where the lever presses into the body) and a check in a bucket of water showed its also leaking air (but only when the lever is pulled via remote).

    Anyway job done, its working and has stopped leaking air and oil.

    Hope that helps someone. Oh and the O ring that failed was a tiny one at the very top of the valve actuator shaft. So small I could hardly measure it but seems common in the cheap o-ring kits I had.

    There may be more elegant solutions so feel free to educate me!


    You da man. Just Googling this problem and ta-da there it is.

    So 2 Q’s, 1. did you need the comprssion tool shown 14 to put the spring back, and 2. any chance you can donate me a couple of ‘o’rings (I ‘as got a J3 and a J4) or tell me where you got the kit from?


    Glad it helps!

    Once the seal head was removed I didnt have to take it apart. It was clear on mine the the o-ring on the other end of the shaft was leaking. It does look like there is a pretty strong spring inside the assembly though!

    I forgot to mention you’ll need a long piece of coat hanger or similar to push the assemebly (out of the post through the small hole where the shaft was) once its unscrewed all the way.

    As for orings – no problem. My email is in my profile. I cant remember exactly which one I used but I’ll send you a couple of each. The o-ring kit was from LIDL / ALDI (branded powerfix).


    Ah, brill. I’ll try Lidl and if no joy email you. Ta

    Premier Icon eviljoe

    Nice one- If you get good at fixing em you might have a cottage industry on your hands, given the number going wrong…

    Will hurry to Lidl for seals for mine…

    Are the innards of the Speedball identical does anyone know?



    Anyone have the spec of the o rings?
    My Joplin 4 just started to leak air from the top and there is no authorise servicing this in my Country.

    I’m hoping to find the necessary parts to let local forks and shock service guy help fixing this


    Just bought one off’n a different forum sounds like mine has the same problem, LIDL here I come!
    Very many thanks for the info you’ve saved me a lot of time and worry
    Cheers Kit 🙂

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