Sponge Posted October 22, 2008 Report Share Posted October 22, 2008 (edited) Hey,I've been about for a while; but only recently I did my first rebleed :$ with a hand by a friend. Partly 'cos my brake never ever needed rebleeding; until now of course; when i tried fitting a Monty splitter and decided to abandon ship...Well, we bled it nice and well; and it 'appears' to have no air bubbles in the system. However, when the TPA is fully wound in; the leverblade seems to wiggle about a lot doing absolutely nothing until a certain point i pull down and it engages the fluid and pushes the pads. Is this normal for a fully wound-in TPA? I try not to wind out the TPA; but I was advised to ever so slightly tighten the little grub screw at one end of the leverblade (right next to the TPA).Yeah, mine's an 04 lever just to clarify!So yeah, when I tighten that grub screw there, it kinda pushes the lever blade southwards a bit; so effectively the travel room for the blade whilst pulling with my finger, is effectively shortened since this little grub screw sets it pulled in a bit. This gets rid of the 'wiggle' I was talking about sorta; but it doesn't seem a perfectly safe method for long term. Since afterall... winding the TPA out is kinda damaging for the lever in the long run too...So yeah, especially for you '04 lever users, can you check if you get any useless wiggling about in your lever blade when the TPA is full wound in? and what do you do to get rid of that useless wiggle? Tighten the grub screw? or what?Maybe something went wrong with my bleed?Any help'd be appreciated!ThanksSponge Edited October 23, 2008 by Sponge Quote Link to comment Share on other sites More sharing options...
G-baby158 Posted October 22, 2008 Report Share Posted October 22, 2008 Mine does that, needs over bleeding but i dont know how to do that. Quote Link to comment Share on other sites More sharing options...
Bionic Balls Posted October 22, 2008 Report Share Posted October 22, 2008 its fine...just use the tpa until the wiggle disappears Quote Link to comment Share on other sites More sharing options...
Mat Smith! Posted October 23, 2008 Report Share Posted October 23, 2008 Yeah mine does it, over bleed it by pushing water into the system untill the pads pop out and then put little allen keys inbetween the pads and the slaves, this should keep the water from pouring out when putting the bleed bolts back in.Mat Quote Link to comment Share on other sites More sharing options...
JT! Posted October 23, 2008 Report Share Posted October 23, 2008 (edited) when i tried fitting a Monty splitter and decided to abandon ship...1. I told you so.2. When you bleed a magura you should always undo the tpa as fully as possible, where ever you have the tpa when you bleed a magura it resets the engagement point (as you put it) to that point so if the tpa was fully screwed in you won't have any extra room to play with.It's just like setting up a v brake with the adjustment on the leaver screwed right out, then when you find the leaver pulls right down to the bars you have no more adjustment left at the leaver.So, undo the tpa as much as possible, and rebleed.Also, the grub screw just ajusts the reach of the leaver, it shouldn't be used for altering the bite point. (Unless you have hope mono trials ) Edited October 23, 2008 by JT! Quote Link to comment Share on other sites More sharing options...
Sponge Posted October 23, 2008 Author Report Share Posted October 23, 2008 Yeah, just went and tried a 1:30am rebleed; nothing special. Thing is, i don't want to use the TPA at all, since it shouldn't really be used and it damaging to the lever in the long run.However; that over-filling idea sounds promising. The main issue I have is when I pull the leverblade; there is 1 or 2mm of 'squirming' just before it mainly engages onto the fluid to push the pads out. I am tempted to think it is air bubbles; but I completely filled the brake until no air bubbles remained. Maguras are fiddly .By the way, for that over-filling idea, how big an allen key in each slave should I be wanting to wedge in? Too much is a bad thing; so I want to keep it just right . Quote Link to comment Share on other sites More sharing options...
JT! Posted October 23, 2008 Report Share Posted October 23, 2008 That wiggle room is probably the room where the leaver isn't actually touching the piston.Did you bleed with no tpa on? Quote Link to comment Share on other sites More sharing options...
Mat Smith! Posted October 23, 2008 Report Share Posted October 23, 2008 Yeah, just went and tried a 1:30am rebleed; nothing special. Thing is, i don't want to use the TPA at all, since it shouldn't really be used and it damaging to the lever in the long run.However; that over-filling idea sounds promising. The main issue I have is when I pull the leverblade; there is 1 or 2mm of 'squirming' just before it mainly engages onto the fluid to push the pads out. I am tempted to think it is air bubbles; but I completely filled the brake until no air bubbles remained. Maguras are fiddly .By the way, for that over-filling idea, how big an allen key in each slave should I be wanting to wedge in? Too much is a bad thing; so I want to keep it just right .like 2.5mm thats what i usually use, and changing the screw at the top of the lever for reach does change the pull because you can use more tpa without it rubbing, if you get me.Mat Quote Link to comment Share on other sites More sharing options...
Sponge Posted October 23, 2008 Author Report Share Posted October 23, 2008 Righty, now I think that it's constantly air being trapped in the Lever. I tried rebleeding it 3 more times, and always the same result. A bit of 'squirm' as I hear the piston trying to push into the lever body, sounds like air bubbles popping.... and then after 2 or 3 mm of that... it finally engages and the fluid is pushed. It appears there are bubbles stuck somewhere right at the piston if that's possible?That's always the problem I'm getting.I basically need to sort out a totally air-free bleed; which so far, has proven to be harder than it seems.Should I pump the lever slowly during certain points of bleeding? Quote Link to comment Share on other sites More sharing options...
Mat Smith! Posted October 23, 2008 Report Share Posted October 23, 2008 Try taking the piston out of the lever and filling it full of water and putting the pison in, its hard to do but works.Mat Quote Link to comment Share on other sites More sharing options...
Alex Dark Posted October 23, 2008 Report Share Posted October 23, 2008 its just where the lever isnt touvhing the piston...you could overbleed it...or stop being silly and use the tpa Quote Link to comment Share on other sites More sharing options...
Sponge Posted October 23, 2008 Author Report Share Posted October 23, 2008 (edited) Damn, I've been away for the last hour or so; and yes finally a rebleed worked! This time I just pumped the lever whilst pushing fluid with the syringe from the slave. So i'd then *slowly* let the lever retract back; whilst at the same time pushing on the syringe so any air trying to force its way back into the lever would be pumped out by the force of the oil coming from the syringe. Got all the air bubbles out this way. Happy happy; my bolts/washers finally came from Stagonset, so I can set the brake up too. Booster for the win, everything just feels so much more solid and responsive now! Gotta go to London now.. I'll have a play on the bike at midnight or something. Thanks everyone that helped! Edited October 23, 2008 by Sponge Quote Link to comment Share on other sites More sharing options...
psycholist Posted October 23, 2008 Report Share Posted October 23, 2008 (edited) If you're using a syringe try pumping the water/oil through quickly - this will tend to entrain bubbles in the fluid. Are you bleeding from the lowest point in the system to the highest? Make sure bubbles are able to rise to the top to get out of the brake - angling the slave pistons and the lever so the exit line from them is their highest point as you pump fluid through will help with this. I find with the newer design Magura lever that it won't fill unless you pump the lever as you bleed it. The lever you show should fill without needing pumping.The lever piston is probably a bit sticky if it's not returning fully on it's return spring - this will leave the lever rattling before it presses on the cylinder, overfilling the brake and pushing the pistons back should force the piston out to engage with the lever, but it's probably not worth worrying about (You may damage the seals pushing the lever piston back the full way if the reason the piston doesn't return is contamination that's got past the lip seal on the piston).This message was sitting on my PC for the past hour before I finished and submitted it - better late than never ... Edited October 23, 2008 by psycholist Quote Link to comment Share on other sites More sharing options...
weebryan Posted October 23, 2008 Report Share Posted October 23, 2008 i bled mine the other day and i found that if you completely remover ther lever altogether then do the bleed (if using water do it underwater or oil use the syringe at the slave/wheel side and pump it up the way with the other bleed screw at highest point possible) and this allows the master cylinder to go all the way back and when you put the lever on with the tpa wound off it will push the slave pinstons in a touch, then loosen a bleed screw a touch and push the extra fluid by pushing the slave in or out or just shy of going right in so thats theres a good pressure in the lines for better response and poweri had to do this cause i had a sticky slave that would not return back even with a good few bleeds and been using antifreeze 3 years running it didnt cure and felt there was not alot of pressure in the line to over come the differnce Quote Link to comment Share on other sites More sharing options...
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