Viewing 26 posts - 1 through 26 (of 26 total)
  • Disc brake bleeding
  • joolsburger
    Free Member

    I have a set of juicy sevens that have been on the bike for a good couple of years possibly 3 years I can’t remember. In that time they have worked faultlessly no sqeals, no rubbing, a few sets of pads. They are still working perfectly, nice and powerful and no issues.

    I may be going away for some spring mountain fun and people suggest a bleed is worth doing beforehand but I’m thinking if it aint broke…

    Thoughts???

    TandemJeremy
    Free Member

    Bleed them. it should be done every year to change the fluid. Fluid degrades over time and dot fluid absorbs water lowering its boiling point.

    The fluid also becomes contaminated which can shorten the life of the seals

    thisisnotaspoon
    Free Member

    If your confident, bleed them, if not get a shop to do them. This is why I like Hope brakes, simple design and can be bled like a motorbike or car with no need for silly addapers.

    PeterPoddy
    Free Member

    but I’m thinking if it aint broke…

    Me too. Apparently Avids can be a bitch to bleed……

    ahwiles
    Free Member

    they’re easy, if you get the right kit…

    stilltortoise
    Free Member

    if you get the right kit

    ???

    A bit of rubber tube, an old jam jar and a little ring spanner is all I’ve ever needed for Hope and Shimano brakes. Oh, and a syringe proves handy too. What’s the deal with Avid?

    isitaboutabicycle
    Free Member

    The Avid bleed kit costs 50 quid. I’ve got a pair of Avids and a pair of Hopes and the Hopes are much nicer to bleed (and require no kit).

    ahwiles
    Free Member

    avid bleed kit:

    the important bits that you can’t easily source yourself are the 2 brass screwy bits which connect the syringes to calliper and lever.

    oh, and the torx-key which fits into the grub-screws in the calliper/lever, which you remove before you attach the syringes.

    isitaboutabicycle
    Free Member

    As well as what’s in that picture, you do actually get some surprisingly useful pad spacers.

    Dickyboy
    Full Member

    Don’t you have to reverse bleed them or something, took my Avid juicy 5’s to the bike shop & even they said they were a bitch to bleed, since then I’ve stuck to Shimano which are a breeze to bleed 🙂

    ahwiles
    Free Member

    nah, avids are easy, you just need the kit.

    (maybe the shop couldn’t be bothered to buy the kit?)

    joolsburger
    Free Member

    My mate has the kit so that’s no problem. The real question here is if my regular riding would show up issues (mostly overheating) that would become apparent in the mountains. 3 minutes downhill here is not the same as 30 minutes in the mountains. Like I said at the moment they are working very well indeed and I’m loath to piss about with them.

    Northwind
    Full Member

    They’re pretty much impossible to bleed without the kit so I’d doubt that. You don’t need the official Avid kit luckily, there are perfectly good 3rd party kits. I think mine is from red dog racing, £13 it was from ebay.

    And yep, I would change it. It’s not neccesarily needed but it’s a sensible precaution. The performance of the fluid will have dropped for sure, whether it’s enough to be a problem nobody can know til you go so it’s best to avoid asking the question.

    torsoinalake
    Free Member

    Might as well learn how to bleed them here, instead of trying to do it on the balcony of your chalet when you are knackered after a day’s riding in the mountains with the lever coming back to the bar.

    thepurist
    Full Member

    If you’ve got the right kit surely you’ll just be pushing new fluid through to replace the old, so there’s no (well, little) chance of introducing air into the system & mucking up the performance.

    The big question is whether you want to find out that you should’ve bled them when they pull to the bars half way down your first big descent on holiday.

    wheelz
    Free Member

    I used to have Avid Juicy 7s and Ultimates. I also had the bleed kit and bleeding both models was a doddle. Just follow the instructions that come with the bleed kit and everything will be fine*

    *But don’t blame me if it isn’t!

    xiphon
    Free Member

    Bleed them once a year, ha!

    Got some perfectly functional Juicy 3s from 2008, still as powerful as they were fresh from the factory.

    joolsburger
    Free Member

    Yeah I suppose it’s sensible to do it. Another little job for the weekend.

    TandemJeremy
    Free Member

    xiphon – its called preventative maintenance. If you are happy to treat it as disposable or take the risk of sudden failure then do so

    for 20p worth of brake fluid and 5 mins a year I just change the fluid every year or so

    The fluid does deteriorate and become contaminated over time. I like my stuff to last.

    ahwiles
    Free Member

    xiphon – Member

    Bleed them once a year, ha!

    Got some perfectly functional Juicy 3s from 2008, still as powerful as they were fresh from the factory.

    just curious, have you ever taken them to the mountains?

    ‘old’ fluid is ‘powerful’ – it just goes a bit weird when it gets hot.

    FYI – don’t ever, EVER, try to lubricate the pistons with anything other than DOT fluid

    thisisnotaspoon
    Free Member

    Also……….

    If you do bleed them, get an old set of pads in there and space them out properly, no point dribbling fluid over good pads.

    nickc
    Full Member

    I’m with PP here, why are you trying to “fix” a problem that doesn’t exist?

    Shimano 525 here, not touched in 5 years. Still work just fine.

    Northwind
    Full Member

    nickc – Member

    “Shimano 525 here, not touched in 5 years. Still work just fine. “

    Mineral oil though, right? Avid use DOT, they act differently over time.

    If anyone’s not convinced, here’s some numbers, based on the DOT4 standards. The minimum “dry” or fresh boiling point for DOT4 is 230 .C. It’s possible to boil it in a mountain bike brake but pretty uncommon. But the wet boiling point is only 155 degrees. The initial performance will be almost unchanged- there’s some minor differences but it’ll still stop you hard. But once you run up the temperatures, that’s when it all goes wrong. And boiling brakes can mean it all goes wrong in a pretty painful manner.

    Now after a few years, the fluid might well not be so wet that it drops that far, but it will have dropped. Which is why so many people ride around in the UK perfectly happy and think their brakes are awesome, then they go to France or Fort William and spend the whole time moaning about fade.

    legend
    Free Member

    Follow the Avid bleeding video (youtube) and you can’t really go wrong. They’re as easy to bleed as any other brake imo

    Scienceofficer
    Free Member

    Like what TJ and Northwind say.

    flippinheckler
    Free Member

    I bought a set of Juicy 7s off here and need to bleed them also somehow remove the hoses to thread through the cable guides (inbred) also one of the pistons on the front is sticking right out and won’t go back in.

Viewing 26 posts - 1 through 26 (of 26 total)

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