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Hayes Nine Lever blade become detached from master cylinder

Simon NotleySimon Notley Posts: 1,263
edited August 2013 in MTB workshop & tech
I have a Hayes Nine Hydraulic brake lever which has failed in a seemingly trivial way, but I cannot see how to fix it.

The lever is connected to the master hydraulic piston by a rod with a ball on the end which sits in a cup on the piston. When the lever is pulled, the rod pushes the piston. There is (was) a retaining piece that prevented the rod-end from falling out of the cup leaving the lever flapping around. This piece - whatever it once was - seems to have self destructed. Does anyone have any idea what this piece is called and whether it is replaceable?


  • cooldadcooldad Posts: 32,599
    Have a look on CRC- they have loads of random brake bits.
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  • dv69dv69 Posts: 19
    There is (was) a retaining piece that prevented the rod-end from falling out of the cup leaving the lever flapping around.

    I'm not sure which part you are referring to but here is a picture of the master cyclinder rebuild kit:


    This image is from the Hayes rebuild guide:


    Are you referring to the small washer or the circlip? Or something else? There's a bushing in there as well. Depending on which part is missing it may be possible to get a replacement from an LBS/mechanic/ironmonger. If you need a full rebuild kit there are a few places selling them. Try searching for "Hayes nine master rebuild" or "HFX9 master rebuild". These two were on the first page of search results: ... p-prod7480 ... rtno=34338

    The rebuild instructions are on the Hayes website here: ... /hfx-9-xc/

    There are also some better images of the rebuild process here: ... yes-hfx-9/
  • Hi Simon
    I have got a big exploded view and use 9’s myself, the actuating rod is held in by a washer and circlip, this then threads into the bush on the lever.
    The circlip is really fiddly to remove but after 5 times of pinging it around the room you will get it on.
    Use a dab of thread lock on the actuator where it threads into the leaver bush DO NOT GET THIS ON THE BUSH.
    Bits are available from usual suspects but if you’re going to bleed them might be just as cheap to get a complete lever.
    If you want a copy of the exploded view let me know and I will email it to you.
  • Simon NotleySimon Notley Posts: 1,263
    Thanks all, that's super helpful. I had looked on CRC, but obviously didn't hit the right search term. I'd also looked on that page of the Hayes website but failed to select the right doc! D'oh!

    The circlip still appears to be in place, it is just the plastic washer that has gone. Looks like I will have to follow the master cylinder replacement instructions and see where I get to.
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