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  1. #1
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    Problem with my Magura Julies

    Back on Thanksgiving day (2010), I took my final ride of the season. Halfway through the ride, I noticed that I had more and more travel to my rear brake level and less and less braking power until I had no rear brake at all. Within the next 15 minutes, the same exact thing happened to my front brake. So I had to walk out with no brakes at all.

    Today I got my Magura bleed kit and I intended to bleed the brakes. I figured that in some weird coincidence all the fluid leaked from both brakes (even though there were absolutely no signs of leakage-the calipers, tubes and lever reservoirs were dry of fluid). Well, I removed the bleed/fill plug on the front caliper and it was full to the point of overflowing and all over the caliper. When I removed the bleed plug on the lever reservoir, it too was full.

    Has anyone had this problem? What gives? Should I go a head and bleed the brakes and see if that solves the problem?

  2. #2
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    Just wondering, how much lever throw do you have now? Is it the same as when your brakes went out on Thanksgiving?

    My guess is, is that there can be a lot of air in there while still looking like everything is full.

    The odd thing is that it happened to both brakes on the same ride.

    If you don't want to try a full bleed right away, maybe try this first, something I found somewhere a while ago (not my words, cut and paste):

    One advice I always like to give is that it may not always be necessary to bleed your Magura disc brake if it feels soft. Tilt the master slightly above horizontal, slowly squeeze the leverblade and quickly release it again for a few times. The air in your system is often in the master and this procedure chases it back into the reservoir where you won't notice it. If this doesn't work you'll have to go through a full bleed, but often you won't. If you want to get rid of the air in the reservoir as well, rotate the master back to horizontal again and push the pads all the way back into the caliper. Protect rotor and caliper for any oil you may spill as you would during a normal bleed. Now open the reservoir, top it off with oil and close it again spilling all excess oil. That's it. No need to go trough a full bleed and you'll be using only one or two milliliter of oil at most!

  3. #3
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    My 02' Julies bypass fluid in the master when it gets cold. Same event as you describe. Maybe it was cold where you are at that time? Mine are unreliable under 40F. I can vary slowly pull in the lever right to the grip.

  4. #4
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    I rode this winter in about 22 degrees and did'nt have any problems. There must be air in your system somewhere. I have 02' julies too. Or you may just have bad seals, but they
    would not go out at the same time if that was the case. If you have a bleed kit then I would give that a try. If that don't work then the seals must be blown or something. Let us know what happens in case we run into the same problem.
    Come to think of it... I'm surprised it even worked at that low of a temp. (Being mineral oil and all)!
    But with all the snow I was riding in I did'nt use them much at all. Whenever I stopped pedalling my
    bike would slow down on it's own.
    Last edited by Bataivah; 03-29-2011 at 10:21 PM.

  5. #5
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    Also, when I flip my bike upside down for a while my lever will go in much farther than normal, but after a few pumps it will build pressure back up to normal. I'm new to the hydraulic brake scene but wonder if there is a little air in the line to allow for expansion when the brake heats up. I say that because I do know when the brake heats up the fluid then there is usually drag because of it. Hopefully someone with more knowledge will chime in soon! If there was no air at all in my system then it should'nt matter if the bike is upside-down of not right? The brake was installed factory (pre-bled) and I never touched it since then, so...

  6. #6
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    A couple of things here...

    It was cold on that ride-probably in the low to mid 30˚'s. I thought maybe the cold had something to do with it. But the bike has been inside where it's 70˚ ever since, and there's no improvement.

    Also, I should have been more clear. Since this happened, I have been able to pull the lever to the handlebar and spin the wheel(s) freely. I literally have no brakes. There is absolutely no resistance in the brake lever and no pad contact on the rotor.

    I'm going to go ahead and bleed them on Friday and hope that solves the problem. If not, I'll come back here to cry. Thanks to all for the advice.

  7. #7
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    Telemarc67

    Sorry you are having issues with your Julies!
    So you definitely have some air in your system, probably a sizable amount for some reason but you will need to start with a couple moves, probably squirting some fluid being the first.

    The cold weather shouldn't have too much affect on your system and our brakes with mineral fluid get used, tested and ridden in much much colder climates like the Ididasport races of Alaska, reference Lou Kobin.www.larutalou.blogspot.com.
    Remember however that all mechanical components will work less effectively in extreme scenarios like the extreme ends of the weather either hot or cold.

    That being said, your scenario is a little odd and for both MC's to stop pressurizing the system seems puzzling.

    May I ask what year Julie's are we talking about b/c we have made them since year 2000?
    Jude

  8. #8
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    I'm wondering if he squeezed them so hard that they blew out the seals.
    Is it even possible to do that?

  9. #9
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    Quote Originally Posted by Bataivah
    I'm wondering if he squeezed them so hard that they blew out the seals.
    Is it even possible to do that?
    No way. I'm not a super aggro rider, and I've never needed more than one finger on the levers. Besides, if the seals failed, I would have noticed brake fluid somehwere...either on the caliper or the lever. I really think I just have a lot of air in the system.

  10. #10
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    If the seals are bad inside the master then they won't leak at all. They will just let the fluid
    go past them instead of pushing the fluid thru the line. Your like me with the levers then...I use 1 or 2 fingers on them and I'm always worried about over squeezing them. Some riders
    are'nt so gentle though.

  11. #11
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    Unless your MC and Caliper are totally full but the entire line is full of air, then it must be the seals. If the piston seals on the caliper went then you would obviously know from the leaking. I'm not sure that you can be using your bike, riding along, and all of a sudden both lines fill with enough air to create total failure.
    With some luck, a nice fresh bleed will fix them and you'll know that was the problem. But how that much air can get in there, all at once, puzzles me. I don't want to wait till Fri. now!

  12. #12
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    Quote Originally Posted by Bataivah
    Unless your MC and Caliper are totally full but the entire line is full of air, then it must be the seals. If the piston seals on the caliper went then you would obviously know from the leaking. I'm not sure that you can be using your bike, riding along, and all of a sudden both lines fill with enough air to create total failure.
    With some luck, a nice fresh bleed will fix them and you'll know that was the problem. But how that much air can get in there, all at once, puzzles me. I don't want to wait till Fri. now!
    Yeah, me too!

    Thanks for the insight. I'm itching to get out and ride. I just got a set of Easton Havoc AM wheels and they're mad because they're just sitting idle next to the woodstove!

  13. #13
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    Quote Originally Posted by Jude@magurausa.com
    Telemarc67

    Sorry you are having issues with your Julies!
    So you definitely have some air in your system, probably a sizable amount for some reason but you will need to start with a couple moves, probably squirting some fluid being the first.

    The cold weather shouldn't have too much affect on your system and our brakes with mineral fluid get used, tested and ridden in much much colder climates like the Ididasport races of Alaska, reference Lou Kobin.www.larutalou.blogspot.com.
    Remember however that all mechanical components will work less effectively in extreme scenarios like the extreme ends of the weather either hot or cold.

    That being said, your scenario is a little odd and for both MC's to stop pressurizing the system seems puzzling.

    May I ask what year Julie's are we talking about b/c we have made them since year 2000?

    Jude, I PMed you on this topic. Thanks for your time.

  14. #14
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    Let me know what the problem ends up being in the end just in case my Julie does the same thing in the future, ok?

  15. #15
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    Quote Originally Posted by Bataivah
    Let me know what the problem ends up being in the end just in case my Julie does the same thing in the future, ok?
    I'll report back Friday night...

  16. #16
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    What am I doing wrong?!?!?!

    The bleed goes fine until the point where I take the bleed fitting (with syringe) off the caliper. As soon as the seal is broken, fluid pours out of the caliper before I can even get the plug back in. I think this loss of fluid is the reason why although there is pad contact and the brakes stop the wheel, I can pull the lever to the grip. This is only a slight improvement over the original problem which was no brakes at all.

    I had to stop working on them because I ran out of fluid. It's all over my shop floor. Arrrgh!!

  17. #17
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    That last bit is tricky, but think in terms of gravity: If your master is higher than the caliper, then when you take the bleed fitting off (with syringe), gravity pulls the oil down and out of the hole. So, what you need to do is either tilt the bike in the stand or take the caliper off and hold it higher than the master, and then take out the fitting.

    Good luck.

  18. #18
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    Quote Originally Posted by knl2stl
    That last bit is tricky, but think in terms of gravity: If your master is higher than the caliper, then when you take the bleed fitting off (with syringe), gravity pulls the oil down and out of the hole. So, what you need to do is either tilt the bike in the stand or take the caliper off and hold it higher than the master, and then take out the fitting.

    Good luck.
    Makes sense. I'll tray that after I go get more fluid. Maybe I should get a gallon!

  19. #19
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    Do you squeeze the lever when you bleed them to get the air out of the Master? When I used to bleed my motorcycle brake, I used to do that. I have'nt needed to do the Julie yet though (or any bicycle brake as of yet).

  20. #20
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    I use pentosin chf 7.1 mineral oil, less expensive. I put the master cap back on before pulling the fitting. Put the plug back in. Take the cap back off. Verify that the pistons are fully retracted. Top off master. Replace cap.

    Make sure the pistons are retracted before topping off the master. The diaphragm in the cap follows the oil down as the level lowers. If in the future you need to retract the pistons for new pads, oil might be forced out the cap as it will hydro-lock.

    I just had wrapped new bar tape for grips and didn't want to rewrap to take off the levers so I did the cap thing and it worked fine.

    Also, as Bataivah said, use the lever to move the piston back and fourth past the hole in the master. You can work out a lot of air that way. You don't have to move the caliper pistons to do this.
    Last edited by 1niceride; 04-01-2011 at 05:44 PM.

  21. #21
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    Where do you get the Pentosin at? It works just as well?

  22. #22
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    Foreign car parts dealer is where I got mine. Its hydraulic mineral oil. Green and white rectangular container. I used it hoping it might help my bypass issue. So far, so good. I think it is a little heavier in viscosity. Do a search here to find out more about Pentosin...

  23. #23
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    Bataivah: Yes, the directions say to cycle the lever about 20 times after pushing the fluid up from the caliper to the master. I did see a few tiny bubbles rise out of the master when I did this.

    1niceride: I did it exactly as you described in your post (as per the Magura directions as well). I made sure the master was topped off. I then replaced the bleed plug on the master. The pistons remained fully retracted and the syringe still attached to the caliper.

    Then, you're supposed to take the caliper off the bike (with the bleed syringe still attached), re-install the wheel, and put the brake pads in the caliper. Next, you're supposed to put the caliper with pads onto the rotor and push fluid into the system with the syringe until you feel resistance. This sets the pistons and pads on the rotor for the particular pad wear, and it puts the maximum amount of fluid in the system. All this went swimmingly.

    The problem is when I go to remove the syringe from the caliper. Like I said...as soon as I loosen the bleed fitting from the caliper, fluid starts pissing out and all over the floor. I no longer have the maximum amount of fluid in the system, and I can pull the levers to the grips. I refuse to let this beat me. I will win!

  24. #24
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    Caliper above the master, and you will be victorious.

  25. #25
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    Quote Originally Posted by knl2stl
    Caliper above the master, and you will be victorious.
    Will report back tomorrow. I think another problem was that I had not yet opened a beer.

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