brake bleeding

Discussion in 'Australian Motorcycles' started by Yeebok, Nov 21, 2011.

  1. Yeebok

    Yeebok Guest

    OK I replaced my rear pads, and decided to bleed both sets - mainly 'coz
    I stuffed up and let fluid out the rear 'coz I forgot to seal the bleeder.

    Anyway as you can expect I've stuffed it up.

    I've sat there for about an hour, open the bleeder, press the lever,
    close the bleeder, release the lever. Now I have not seen any fluid come
    out of the rear brake since god knows when. I've even left it sat
    overnight with the bleeder open and the cap off the rear reservoir
    hoping gravity would help.

    I can't actually get the top off the front brake reservoir but could 2
    days ago. Of course this only became an issue once I needed to get it
    off to top up the front. I can sit there and flap the front lever around
    to absolutely no avail, I get absolutely no pressure.

    I don't have the funds to buy a brake bleeder kit so I am stuck with the
    manual process. I have absolutely no brakes and am of the opinion I've
    got air in half the rear hoses.

    I've put WD40 on the screws for the top cylinder but still can't undo
    them, and want to avoid burring them out.

    Any tips or advice ?
    Yeebok, Nov 21, 2011
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  2. Yeebok

    atec77 Guest

    slip some tube over the bleeder once having established it's possible to
    open it , add a little clean fluid to a jar and drop the end below the
    bleeder into the jar and pump the peddle several times ending under load
    , crack the bleeder and release a little fluid . Close bleeder and
    release peddle , wait a minute then repeat until the fluid runs clear ,
    and keep topping the master .
    Find a tight ring spanner for the other bleeder and make sure it fits
    well , tap to release with a fibre hammer in the right direction and
    bleed , by submersing the end you ensure only fluid gets drawn back if
    you err . I assume a couple of things , the master cylinder is higher
    than the brake and bleeder and you have a clue , good luck


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    atec77, Nov 21, 2011
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  3. Yeebok

    atec77 Guest

    Oh and if really wont bleed there is another way which I am happy to
    explain , it works on Bmw's quite well


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    atec77, Nov 21, 2011
  4. Yeebok

    Yeebok Guest

    I assume a couple of things , the master cylinder is higher
    That latter part seems to be the problem..
    Yeebok, Nov 21, 2011
  5. Yeebok

    GWD Guest

    Get on the phone and find someone who knows about this stuff, and pay
    that person to come and show how it's done. Brakes are too important
    for blind experimentation. Much better to learn from someone who is
    there in person.
    GWD, Nov 21, 2011
  6. Yeebok

    atec77 Guest

    Oh , ok email your cell number and I will explain how to use an oil can
    , will take 2 minutes to fix them


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    atec77, Nov 21, 2011
  7. Yeebok

    will_456 Guest

    It doesn't take too many pumps to empty the resovoir and start putting
    air in your system. You need to get the cap off and top it up first.

    If the end of the tube is submerged in fluid are you getting bubbles in
    the bottle when you pull the lever in?

    Should be. If not nothings coming down the line.

    If it hasn't been done for a long time it's not unusual to stuff it when
    you push the pedal down all the way forcing the piston into corrosion
    and shit that tears the seals.
    will_456, Nov 21, 2011
  8. Yeebok

    Yeebok Guest

    OK, where the lever pushes the rubber seal into the master cylinder
    (rear), there is occasionally a pop type noise - the rubber seems to be
    pushing in OK otherwise though, but it seems like it's not always
    pushing completely (as if it's not coping with the back pressure).

    Laying under the bike and watching, there are no leaks, but the rubber
    seal does not always pop out.

    That said, cap off and so on, I am not getting any reaction from the
    rear lines.

    On the front if I open the bleeder it sucks fluid in from the cup/tube,
    'til I press the lever whereupon it pushes out whatever it's sucked in..
    but since I can't get the <swear> cap off, I can't top it up and start
    fixing the problem.
    Yeebok, Nov 21, 2011
  9. Yeebok

    Nigel Allen Guest

    Presuming the "top reservoir" is handlebar mounted, can you get a strap
    wrench around it? If you don't have a strap wrench then you could try to
    jerry-rig one from a leather belt and a suitable sized slotted bar of
    some description.

    Stupid question, have you tried locking a pair of vice grips onto the
    cap and giving it a smart "smack" with a Birmingham Screwdriver? A
    little percussive maintenance is often enough to loosen the thread seal.

    Note: Righty Tighty, Lefty Loosey.


    Nigel Allen, Nov 21, 2011
  10. This is the way I do it.

    Firstly, this is a two person job. If you work alone, hire a trained
    helper monkey if you need too. Don't care how you do it, you need two
    bodies here.

    Get the lid off the reservoir somehow. I don't care how, just get it off.

    Fill the reservoir to the fill mark. With fresh fluid. Buy fluid if
    you have to.

    Pick a wheel to do first. Start with the fronts, then the rears.

    Use a ring spanner around the bleeder valve.
    And only a ring spanner. Again, buy one if you have to.

    Attach a rubber hose to the bleeder nipple, and let it dribble into a
    jar or something clear like that, so you can see what's coming out.
    This is important, you need to see the juice.

    Get your friend, wife, neighbour, chimp, or whoever to stomp on the

    While they're applying pressure, open the bleeder a bit, and watch the
    old fluid come out.

    Here's the tricky bit, you need to close the bleeder BEFORE their foot
    hits the floor.
    An important bit I cannot stress enough, when they lift their foot
    (after you've closed the bleeder) for fecks sake, make sure they do it

    This is why I specified a *trained* chimp. I've seen some untrained
    zoo graduates who lift off too fast, and squirt fluid from the reservoir
    all over your paintwork.

    Check the reservoir and top up as required. Now you know why the lids'

    Repeat till you get clean fluid coming out the bleeder end.

    Once that wheel is done, go onto the next.

    Remember to return the Monkey when you're done. The overdue rates are

    You won't believe what fresh fluid and a GOOD set of pads will do. I
    had my VB Commodore with high temperature juice and Bendix metal kings.
    Had it screaming around Eastern Creek (Bob Jane Great Australian All
    Rounders for tyres - yes, I'm a glutton for punishment) and brakes
    didn't fade a bit. At all. The tyres turned bright blue, and other
    things broke, but the brakes were good.

    In contrast, every factory standard vehicle we've been in, loses its
    brakes after the first stop. But around the track, we just work around
    that by not using the brakes. Throttle to the floor, and opposite lock
    into every corner scrubs off enough speed to do the job. This has the
    added advantage of having everyone in front of us move out of the way
    and wave us buy.
    Perhaps because we're faster than them, or perhaps because we're
    driving like fucking lunatics - who's to say?
    We prefer functional brakes though. You get faster lap times, longer
    lasting tyres, and you don't get that stern talking-to in the pits when
    you're done.
    John Tserkezis, Nov 21, 2011
  11. John Tserkezis wrote:

    Just noticed this was the bike group, and I was jabbering on about
    four wheels.

    Anyway, same as before, except, you squeeze instead of stomp on the
    fronts, and repeat the reservoir for the rear (as required, some are
    cable driven).
    John Tserkezis, Nov 21, 2011
  12. Yeebok

    Yeebok Guest

    Yeah the front reservoir is handlebar mounted.

    Sadly though it's some fucking square thing with recessed screws..

    After someone else having a look at it today it's letting some WD40 soak
    in to the screw I can't get out on the front reservoir (one Philips, one
    flat .. ffs). If I run a tube from the bleeder to a cup with some fresh
    fluid in it, when I open the bleeder it pulls fluid in and when I hit
    the lever it pushes all the fluid it just sucked up out (as it should) -
    but I can't get more in the top end 'til I can get the top off.
    Essentially it seems to be working OK and I am doing the right thing,
    but can't progress that 'til I can get the lid off.

    The rubber seal on the rear one doesn't seem to be pushing anything.
    Ican open the bleeder and run the tube into the same cup, reservoir cap
    off, etc and nothing happens (aside from the lever moving). I get the
    feeling the rubber seal is stuffed even though it does seem to pump -
    there's the occasional faint pop type noise and the rubber seal pops
    outward a smidge. As mention above I am reasonably confident I've
    completely fucked that up and have more air than fluid in there.

    I will try Atec's suggestion tomorrow to try and pull fluid through - is
    it possible that it would work OK when full of fluid but as soon as it
    got air in there it won't?
    Yeebok, Nov 21, 2011
  13. Yeebok

    Yeebok Guest

    I'm doing pretty much as you're describing, but on my own. I did wonder
    whether you thought I meant a cage when you said two people - I can
    reach the bleeder and lever pair with each hand whichever end I am doing.

    Initially I didn't have tubing, but since it's a concrete floor I just
    put towels over the bike since I was not sure how far it'd squirt
    (that's what she said). Fluid came out and went a reasonable distance.

    Bought fluid, using an 8mm ring spanner (ring end) on the bleeder. Got
    fresh fluid and some nice 1cm tubing.

    The only thing I am doing differently, and not sure if it is important,
    is I was doing it this way :

    (Reservoir top off)

    while (old fluid exiting bleeder == true);
    Open bleeder;
    Completely depress brakes;
    Close bleeder;
    Release brakes;

    So ..
    I would have thought holding the lever completely in was the correct
    way, can you explain this part ? I am wondering if it is related to my
    rear brakes not pumping now (shorter pump, less pressure, therefore the
    rubber part's less likely to pooch out) - the really odd thing there is
    I can't find any leaks near it at all. The rubber seal's dry as you know

    The most annoying part of this is I probably didn't need to bleed them
    but thought it was a good idea since it has not been done since I got
    the bike, and I've put about 35,000km on it.

    Now I'm pretty convinced that bleeding the brakes was a good idea, so
    long as it wasn't *me* doing it :)

    So anyway a quick summary - I reckon the rear's drained very badly to
    the point where the master cylinder quite probably has air in it. The
    fronts seem OK bar the fact I can't get the lid off.
    Yeebok, Nov 21, 2011
  14. Yeebok

    Yeebok Guest

    Oh this is what the front reservoir looks like.

    At the moment I'd be quite happy to take the top off it with an angle
    grinder but I dare say that'd be counter productive.. :)
    Yeebok, Nov 21, 2011
  15. Yeebok

    atec77 Guest

    atec77, Nov 21, 2011
  16. Yeebok

    F Murtz Guest

    Get a set of things like this for next time if you have already
    destroyed it or for now if you have not.
    F Murtz, Nov 21, 2011
  17. You should be able to let the master cylinder self bleed, fill the
    reservoir, put your new pipe in the bleed screw, open the screw, sit back
    and have a coffee while you are watching for any movement
    Try filling the top reservoir with fluid, then open the bleed screw and
    watch for any fluid coming out, this is where you can put your brand new 1cm
    tube to good use, on the bleed screw.
    Close the bleed screw
    As you are watching, "SLOWLY" depress the brake lever, you may see a small
    fountain of fluid rise, then let the lever go as fast as you like, the speed
    will not make any difference,
    then open the bleed screw and while still holding the lever in, close off
    the screw,watching still, you may see small bubbles of air.
    Keep doing this process, till you see no air returning .
    You may then notice that the lever will start to get firmer in the action.
    Most master cylinders I have come across in bikes, have been located above
    the slave cylinder therefore, being able to self bleed over a period of
    time, about an hour or so, or even overnight is better
    George W Frost, Nov 21, 2011
  18. Yeebok

    thefathippy Guest

    Can't bleed them without getting that sucker off, AFAIK. And you have
    to get it off before you start squeezing out fluid. Otherwise, you
    can't replenish the level as it bleeds out, and bingo - air in the
    system. As you've since discovered. Maybe a hammer drive to attack the
    bolt/screw? Might break the casting on the mount if you hit too hard,
    so be careful! I have found that those screws do tend to corrode into
    place (or maybe they were loctited in), so something that breaks the
    corrosion is the go.

    Once it's off, then you can bleed off all that air you've added -
    adding fluid as you do so. ;^)

    Or, as someone said, get someone who knows what they're doing to pop
    around and give you a hand.

    Tony F
    thefathippy, Nov 21, 2011
  19. Yeebok

    Nigel Allen Guest

    I don't know how "ept" (as opposed to "inept") you are mechanically but
    here's an idea for you to try (with apologies if I'm teaching grandma to
    suck eggs).

    Get a screwdriver that has a blade in good condition and fits the
    screw-head really well, and a hammer.

    Put the screwdriver in the slot and grasp with your fist (thumb at the
    top) as if you were trying to undo the screw, putting as much pressure
    into "down" as "twist". Now repeatedly hit the end of the screwdriver
    handle with the hammer while keeping the unscrewing pressure on.

    Poor man's impact driver. It does work.

    Nigel Allen, Nov 21, 2011
  20. Yeebok

    Nigel Allen Guest

    Nigel Allen, Nov 21, 2011
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