Just got the new xt brakes under warranty as had my old ones replaced too many times, anyway I've done 5 rides now and have found that when feathering the rear brake for more than about a minute the lever seems to lock up and give a feeling of being solid with no more movement of the lever??
Once I let off the brakes it works as normal, but does the same again on continual use?? Front brake doesn't seem to do it, but haven't used that as much so can't really tell
Any advice or has anyone else experienced similar issues???
pump ?
maybe needs a bleed
oh, and try not to drag your brakes
The M8000 model?
I found my rear lever was firming up significantly under braking. I've assumed it's air in the system, so just waiting for the Epic Bleed kit to arrive.
Feathering the brake for 1 min sounds like dragging the brakes to me. No wonder you are having problems. Try shorter harder braking instead.
mine are working fine which is a bit of a miracle as I chopped the hoses and fitted them myself! first time I've fitted disc brakes.
Being on the brakes for a full, continuous, minute is a REALLY long time. You be building up serious heat in that time which will expand the fluid, pumping the brakes up.
Where are you riding? The Alps?
tomhoward - MemberBeing on the brakes for a full, continuous, minute is a REALLY long time. You be building up serious heat in that time which will expand the fluid, pumping the brakes up.
Where are you [s]riding[/s] mincing?
FTFY
The piston will be on its way to jamming. This batch of Shimano brake I think are worse than the last. My new xtr and saints are both away under warranty.
Rustychain yes same problem, maybe 1 minute was a tad of an exaggeration thinking on lol
Mince is always on the menu as I'm always behind tops5
Ive got the same issue after shortening the rear hose.
I'm assuming that it needs a bleed.
Full on mincing from me too, not a STW Warrior like the heroes above 🙄
My M8000's have a similar problem after shortening using the no bleed method, so going to bleed them anyway this weekend.
Out of interest, does it matter what temp the brakes and oil are when you do a bleed? Just wondering as my bike and oil are currently in the garage so thinking will it be better to move them inside for a while beforehand to warm up. Tried searching online but can't see anyone else asking same question.
Buy Hope 😉
Regardless of whether you're dragging your brakes or not, they shouldnt be pumping up.
It'll be intolerance of air in the system, where the air is expanding after getting warm, and that makes the lever feel stiff.
Give them a bleed, and they should be better. If not, buy some SRAM Guides.
Oh how times have changed, when a SRAM brake is more reliable and tolerant to air than a Shimano 🙂
Best Shimano bleed trick I've used is to just do a "top up" from the leaver. It worked a treat on my SLX and XTs and really brought back the feel in the brakes again and it only takes a minute to do and you can leave your bike all set up.
You'll need the leaver funnel and some Shimano mineral oil.
Put some mineral oil in the funnel (less than half full).
Make sure the plunger is in secure.
Open the bleed port on the leaver and don't lose the o-ring.
Attach the funnel to the leaver carefully.
Undo the plunger and press the brake leaver and watch bubbles come out. You can tap on the hoses and all that too if you want.
Then put the plunger back but hold on to it and carefully take it out again repeatedly keeping it in the oil at all times. Doing this creates a mini vacuum at the plunger and you can watch bubbles of air get pulled out. The air is being replaced by the oil and so your brake will firm up. Keep doing this while pulling the leaver until the leaver feels "correct" again or just firms up.
Bung up the plunger when you see no more bubbles.
Carefully remove the funnel and just drop a drip of oil on the bleed port to fill it up.
Replace the bleed screw and mop up any excess oil.
Test your brakes and ride.
They should feel like new again.
If you see dirty oil during this process you're best to flush it out with new and do the full bleed properly.
It's a "quick fix" to reset leaver feel.
I'm assuming the M8000's have the same setup for bleeding as the older XT/SLX (2013/2014).