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Any idea's where air could be leaking into a shimano (LX dual control) brake system, as it will not bleed free of air, no matter how many times I flush fluid through it, lots of tiny air bubbles appears in the the fluid just when I think it's cleared.
I've tightened up the connections to the calipre & lever as much as I really want to & there's no fluid leaking out anywhere.
master cylinder seals? Level too low in the reservoir sucking in air? I cannot see how else you could get air in but no fluid out.
Are you bleeding it correctly? Some systems need odd methods
made the mistaker of running the reservoir too low but have put enough through to correct that. Have been bleeding them by push the fluid down from the lever and out the calipre... I would refill it bottom up but I can't locate a 100ml syringe to do it (without buying a bunch of usless ones offa ebay).
PPl always say that shimano aren't servicable, so can the master cyclinder seal be replaced?
I've had 2 sets where a caliper piston seal went. I could bleed it OK, but then would lose power with each ride and I got a tiny bit of fluid leaking onto the back of the pads which burnt off (pad over cooker) with loads of give-away smoke.
had another set where I could never bleed it right: air bubbles just kept on coming. I figured must be one of the lever seals: replaced the whole lever and problem solved.
AFAIK you cannot replace the seals on the Shimanos: its a new caliper or lever if anything goes. Can usually pick them up off ebay cheapish.
I had this problem on SLX brakes, my solution was bleeding them normally then :
[*]close bleed nipples up[/*]
[*]pull lever and hold in place with a laccy band (to close port in master cylinder)[/*]
[*]attach completely full syringe & hose to calliper[/*]
[*]open calliper bleed nipple[/*]
[*]pull and push fluid back and forth (hold syringe in a vertical position where any tiny bubbles inside will float to the top)[/*]
[*]hope that the pressure causes a load of air to come out of the system[/*]
[*]???[/*]
[*]profit[/*]
Also warming the fluid up beforehand seemed to aid the process of getting bubbles out (did mine when it was absolutely freezing though)
Would you like me to send you a 60ml syringe?
[i]AFAIK you cannot replace the seals on the Shimanos: its a new caliper or lever if anything goes. Can usually pick them up off ebay cheapish. [/i]
These were off ebay....
Boobs, I'd love one.. I'm struggling to locate on without paying ridiclous amounts of P&P
You don't need a very big syringe to bleed Shimano brakes, I cope fine bleeding my XTR's with a 5cc one that I got from my local health centre pharmacy.