 You don't need to be an 'investor' to invest in Singletrack: 6 days left: 95% of target - Find out more
So i've bleed my disks brakes repeatedly and i find that the lever moves about 1cm before the pads are fully engaged. The rear brake lever moves about 2cm which feels right to me, however after repeated attempts i cannot seem to adjust the pad bite (contact point) or increase the lever movement to a comfortable position.
The free stroke screw does little, it makes the lever action feels mushy to me but does not seem to help.
I've been using the bleed up to funnel, funnel down to calliper bleed process. Action is sharp and immediate but all within a tiny amount of lever movement. It seems as though the pads are not retracting back far enough into the calliper body.
Brakes are fairly new, shimano mineral oil being used.
any tips or suggestions?
Too much fluid in brake?
My No.1 tip for improving XT the brakes - leave a teeny (really really teeny) bit of air in the system, makes them much more progressive and friendly (EDIT: just re-read my comment - I mean in the reservoir not the hoses/caliper!)
leave a teeny (really really teeny) bit of air in the system,
How would you possibly know that had happened? Superman x-ray vision?
OP, you've got the opposite problem to me. I find there's too much lever through with XT brakes. I'd love 1 cm of movement before they start to work!
You can get air in the reservoir by simply not filling the reservoir to the top.
Fixing too much movement is pretty easy. Set your reservoir bleed cap to be level to the ground. Take the reservoir cap off, you will probably see the oil level is not to the top. With the cap off, pump the levers - more air will probably escape as bubbles. Once all the air is out, top the oil up to be to the top of the bleed hole, and then add the cap again, cleaning up the excess. That should sort you out.
[quote=binno]It seems as though the pads are not retracting back far enough into the calliper body.
Did you use a bleed block? I.e. bled with the pistons fully pushed back..
[url= http://singletrackmag.com/forum/topic/freestroke-adjustment-on-current-xts ]have a read at this thread[/url]
How will leaving a bit of air in the reservoir make any difference to the lever travel?
Its just a reservoir, it plays no part in the braking process, just keeps air out of hoses.
Too much fluid in brake?
I'd have a go at opening the reservoir cap, push the pads back if they need to go back, clean up the excess oil and replace cap.
The bite adjust can make it tricky to adjust, if its either fully in (might be out) they are a bugger to bleed. I screw in and out the bite adjust when bleeding, nearly always gets another bubble out.
If the front and back are fully bled and the pistons are pushed right back and the lever reach and bite point are the same on both levers then they should have the same throw.
Bigyinn, air the reservoir will compress.
I've tried this tip on PB and I can see how it can help, you can use the small Shimano bottles with the endy pointy bit.
[url= http://www.pinkbike.com/news/tech-spotlight-5-minute-bubble-bleed-2014.html ]http://www.pinkbike.com/news/tech-spotlight-5-minute-bubble-bleed-2014.html[/url]
They have an overflow in the lever so if you prise the pads apart slightly, it should give you more travel by squidging out a little oil.
The free stroke does nowt.
I bleed my XT's to how I want by pumping the pistons out before I bleed caliper to funnel. If I want more travel, I space the pads apart a little more before I bleed.
It's a black art.. 😀
[i]The free stroke screw does little, it makes the lever action feels mushy to me but does not seem to help.[/i]
[i]The free stroke does nowt.[/i]
It does if you bleed the brake with it screwed out. This effectively makes the lever reservoir slightly larger so you get more fluid in. When the lever cap is back in you can use the little silver screw to decrease the volume of the master cylinder and adjust the bite point.
Well mine did nowt from new so I can only assume Shimano didn't bleed them right?
You can pop the pistons out by an extra mm or so before you bleed.
Yes I've used the yellow bleed block, with the pistons pushed right out.
Not tried the free stroke pre bleed though, will give that a go.
It does feel like there's too much oil i there, if that's possible? something must prevent the pads from backing out all the way. When i've completed a bleed, i pump the lever a good 5 times before the pads seat to bit agains the rotor (theqhen thy centre to it) it's just that they do not back off as far as the original post bleed position.
Reading the post to other links now.
I bleed my XT's to how I want by pumping the pistons out before I bleed caliper to funnel. If I want more travel, I space the pads apart a little more before I bleed.
That follows. I'll be trying this. Thanks!
I might try and shave a bit of the bleed blocks until I have it just how I like it.
Still non the wiser.
Going to investigate squeezing the lever via the bottom down bleed procedure. Maybe releasing some oil at the calliper stage mid squeeze, will set the bite point?
Best pre-trying it for real idea i can come up with.
scruff - Member
Bigyinn, air the reservoir will compress.
Yes, but the reservoir is not part of the braking circuit, its an open system so when you pull the lever the reservoir is "locked out". Its there to ensure that only fluid is drawn into the system when the pads wear and the pistons move in more to compensate.
I cant see any need for any air in the reservoir, unless Im missing something fundamental?
Calipers need to be aligned with rotors, once calipers are aligned you can go about aligning the pistons.
If the calipers are not aligned, the pistons compensate for it and it can cause symptoms such as yours, it might have nothing to do with the way they have been bled!
It could be your getting excessive travel on the rear because of the above.
Try this.
Calliper off and using plastic tyre lever push pistons fully in.
Then using largest brake block bleed brake.
Now loose refit caliper with pads and pump lever until pads touch disk.
Remove caliper and gently squeeze the lever so the pads move inboard and let when the pads have moved in slightly further and the pads will retract when you let go.
This will place the closer to the disk and thus give immediate grab.
NOTE - if you squeeze hard/too much the pads could touch and retract enough to fit over the disk.
Also this will give you incredibly sharp brakes, so be-careful of face plants
I've found if you just unwind the reach adjust screw all the way out. And have the lever adjusted so that it's as far from the bars as possible..
Bleed the brakes, push fluid up from the caliper into the shimano screw in do dar..
Then suck fluid back down, keeping the do dar topped up..
I do this a few times until no bubbles come out either end.
Bleed the brakes without the bleed block, just leave the pads in and use the disc in the middle.. If you trust yourself not to spill oil 🙂
I've found if you just unwind the reach adjust screw all the way out. And have the lever adjusted so that it's as far from the bars as possible..
I've always wondered f this is why I don't always get a great bleed, will try this too.
All tips taken onboard and used previously. I've discovered what the issue was however, pad width.
I was using some oil damaged pads, 1 cheap shimano pad and 1 superstar (cheap) pad, which turned out to be a fair bit wider than the shimano pads with fins. Fitting the corrected pads that came with the brake led to what is now an amazingly well bleed and running brake.