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  • Embarrassed to say – don't have a clue how to fix my front disc brake.
  • makecoldplayhistory
    Free Member

    I went to ride my wife’s bike to check I’d indexed her gears properly and the front brake doesn’t work! I’ve never bled or touched a disk brake for maintenance before.

    It’s a Mono M4 as in pic below. There seems to be some fluid around the reservoir cap seal on the lever. Squeezing the lever makes the pads move a little, but not enough to stop the wheel whatsoever.

    Does anyone have a link to a good guide? I don’t have a bleed kit either. I do have a syringe and there are loads of motorbike shops around where I’m sure I can buy some DOT 5.1. Can I remove the reservoir cap, pour in a little fluid, put the cap back on and see what happens?

    I’ve been in Thailand for a week and although I did bring spares, disk brake seals weren’t among them. For the leak to have occurred, is the seal likely to be broken? It’ll cost me £10 in postage from CRC. If needs be though, is this what I’m after?

    http://www.chainreactioncycles.com/th/en/hope-complete-seal-kit/rp-prod49368

    Thanks a lot,

    Mike

    ahwiles
    Free Member

    it’s more likely that something has just come loose – it does happen – and fluid has leaked out, air has leaked in.

    find a friend who can fix it, shower them with gifts and money in return for their work.

    failing that, watch videos on youtube, get tooled up, giveyourself a day (or 2) and get stuck in.

    while you’re doing this, remove the brake pads, and hide them somewhere clean, dry, and safe (from your oily hands).

    when you’re done, clean the bike – brake oil will ruin the paint, and god only knows where you will have spilt some.

    (and get a new nipple cap)

    no_eyed_deer
    Free Member

    IME if Hope M4’s have been upside down – or laying sideways – for a while, air will move from the reservoir to the brake lines and cause this problem.

    Fix by repeatedly pumping the brakes while the bike is vertical. You may need to do this for 5 mins or so.

    If this doesn’t work, set the brake levers so they are horizontal on the bar, pull the levers to the bar with zip-ties and leave over night. In the morning remove the filler caps and top up to the brim with fluid. Re-fit caps. Job done.

    If the rear is at fault, you may need to de-tatch the rear brake caliper and line it up directly below the lever – so that it falls in line directly below the lever. Always try to imagine air bubbles flowing upward and into the reservoir – if that helps to picture it.

    I wouldn’t bother with all that beeding faff IME. Hope’s are quite easy to let ‘bleed themselves’ if you do it this way… 🙂

    Trailseeker
    Free Member

    If they were working fine before & you’ve not done anything to them, I’ve found that canting the bike over to the left (so any air bubbles can rise to the lever without getting caught in a high point) then rapidly pumping the lever a few times & tying then lever back to the bars for a few hours with a cable tie works.

    smatkins1
    Free Member

    You don’t need a kit to bleed hope brakes. Just a bit of plastic pipe from the plumbers section from B&Q to fit over the nipple on the calliper (the stuff they sell if a perfect fit!).

    There is a good hope video on youtube to show you how.

    Worth giving them a bleed and checking everything is tight. They’re honestly incredibly easy to bleed!

    notmyrealname
    Free Member

    You don’t need a blled kit to bleed Hope brakes, just a length of hose and some fluid. You can get the right size hose from aquatic shops as it’s used on fish tanks.

    There’s a video here to show you how to do it.

    http://blip.tv/mtbcut/how-to-bleed-brakes-1576358

    jambalaya
    Free Member

    Wife’s bike has Hope brakes and braided hoses – nice !

    It does sound like air in and/or fluid out, I assume brake lever pulls all the way to the bars. I lived in Singapore and there were plenty of local bike shops (and very cheap). Thailand has an mtb “scene” – where are you based ?

    gordonb
    Free Member

    yup, easy to bleed, tools required are length of tubing, empty water bottle to catch and dispose of the brake fluid, 8mm spanner, and dot 5.1 oil.

    Open reservoir cap, the missus at the lever end, you at the caliper end, you open bleed nipple 1/4 turn, shout open, she squeezes brake but doesn’t release lever, she shouts squeeze, you shut nipple, shout close, she releases lever then pours new brake oil into reservoir. Repeat til it all flows nicely.

    makecoldplayhistory
    Free Member

    Thanks for the relplies.

    It sounds like I can give bleeding a go. Hopefully I won’t need a new seal simply because I’d imagine Hope spares are less common than say Avid.

    My wife’s bike’s sneakily been built up for me to use as a hooligan bike at the swap of a seatpost / saddle. She thinks it’s hers… 🙂 she’s got floating disks now too!

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