Bleeding brake problem

JayKingFunk
JayKingFunk Posts: 411
edited March 2016 in MTB workshop & tech
Just tried for the second time to bleed my brakes.

Followed all the instructions, got tonnes of bubbles out, was very patient, repeating the process several times and still no good.

The leaver pulls all the way to the bar with ease and have virtually no affect on the calliper.

Problem started when I undid the grub screw at the calliper and lost some fluid in the process a while back. I'm wondering if I need to put more fluid in as opposed to just bleeding the system?

Brakes are Formula RX and I'm using Dot 4 fluid as suggested by manufacturer.

I've serviced forks, swapped bottom brackets, true'd wheels and done pretty much every other job on a bike in the past but for some reason I can't bleed my bleeding brakes!

Brakes look quite healthy, as do hoses and they were perfect before I stupidly let some fluid out...

Any help would be greatly appreciated.

Thanks in advance, J.
I love the sound my tyres make on dusty single track!

Comments

  • nicklouse
    nicklouse Posts: 50,675
    You have failed at bleeding the brakes.

    Re do it.

    Why talk about adding fluid? You do that when you bleed the brakes.

    If you have undone the bleed nipple after bleeding you will need to rebleed.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • JGTR
    JGTR Posts: 1,404
    You fill the system with fluid when you bleed it so lack of fluid won't be a problem.

    I've had a similar thing, needed new caliper,
  • Herdwick
    Herdwick Posts: 523
    good luck bleeding the formulas :)
    When afriend came to me to help him bleed his, I binned them, he bought a pair of deores and evere since he can haul to a stop
    “I am a humanist, which means, in part, that I have tried to behave decently without expectations of rewards or punishments after I am dead.”
    ― Kurt Vonnegut
  • The Rookie
    The Rookie Posts: 27,812
    2 things with Formula
    1/ you need to keep faffing at the lever end to make sure all the air is out, it doesn't like coming out the nooks and crannies
    2/ the diaphragm that creates the expansion volume (so the brakes continue to work as the pads wear) is much stiffer than many others so you need to almost pressurise the system at the end of the bleed process.
    Have you watched the official formula video on YouTube?
    Currently riding a Whyte T130C, X0 drivetrain, Magura Trail brakes converted to mixed wheel size (homebuilt wheels) with 140mm Fox 34 Rhythm and RP23 suspension. 12.2Kg.
  • UncleMonty
    UncleMonty Posts: 385
    Agreed with point 1 above.

    I took mine off the bike to bleed, clamp the lever to a broom handle and keep upright with the port at the top.
  • The Rookie
    The Rookie Posts: 27,812
    100% you can never bleed a formula on the bike, just wasting time trying, that's by design, not a 'fault' as such and is common to most flip flop levers.
    Currently riding a Whyte T130C, X0 drivetrain, Magura Trail brakes converted to mixed wheel size (homebuilt wheels) with 140mm Fox 34 Rhythm and RP23 suspension. 12.2Kg.

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