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Pads wear quicker on the front though.
Depends where you ride and in what weather. I go through rear pads 3x faster than fronts due to a lot of wet riding (puddles as well as in the rain) kicking up the grit and sand onto the rear caliper and disc chewing up the pad. The front doesn't get anywhere near as much crap on it so the pads last a lot longer. In winter I can still get away running softer pads up front (uberbike semi-metallics are my go-to, nearly as good as the Rahox ones but significantly cheaper!) whereas I need to go to sintered on the rear to not have to change then every ride or so. Go through rear discs faster too. Been the same on my Shimano and Hope brakes.
I currently have 3 sets of Shimano brakes (2x Deore, 1 XT) and they all work fine. I did have to bleed the rear XT a few times to get all the air out of it initially (on my 5 so hose off to fit) and found standing the bike upright really helped. One thing I have noticed is that Shimano pads are noticeably thicker than aftermarket ones, could this be a problem? I found the OE ones stopped working once they'd worn down to the end of the chamfered part of the pad so you're not getting any more useable pad depth but maybe the caliper is set up to use thicker pads and this is causing issues? If it is maybe fitting some of the aftermarket fins would space the pistons out further, sort of simulating the thickness of OE pads.
If the XT's show any sign of playing up I will be going back to Hope. Only switched to XT as A: my rear Hope was old and needed upgrading to keep up with the front and B: I was fed up of constantly having the wrong spare pads in my pack (Shimano when riding the bike with Hope and vice versa). It was cheaper to switch one bike from Hope to Shimano (actually made cash 😀 ) than put Hope on the other two bikes!
After reading all this I'm keeping my fingers crossed as we haven't experienced any of the problems and are running eight sets between us.
Well, today I went to swap my rear pads and noticed a stuck piston. My attempts to press it back in resulted in a cracked, leaking piston.
Just got a new 800 caliper and lever from lbs as I need it for tomorrow.
May explain the poor performance on that set.
I can't believe what a minefield I opened up with this thread. I was expecting quite a straight forward answer, not the consensus that this is a widespread problem with no real solution and nobody really knowing exactly what the cause is!!
Errr, perspective required, please. I haven't bothered to count the number of individuals who have posted on this thread, but let's take the number at the top of each page, which says 68. Now, before starting a zombie shimano brakes apocalypse, I wonder how many units have been manufactured in the last 4 years or so? Hundreds of thousands? In percentage terms, possibly acceptably small enough to warranty.
Of course, there is the possibility of death, at which point my perspective plea falls somewhat short and I just hope the tabloids don't get to hear about this epidemic.
Internet eh? 😉
P.S. Stealth edit 😉
OK but its not that as my little bottle says "Shimano" on it. Not that other mineral oil would behave any differently.
Shimano brakes HAVE to have shimano fluid in them. It's a propriety fluid. All 'mineral' fluids are not the same. It affects the seal performance.
Just to add some more food for thought, mine started to do it when I took the wheel out and put the bike in the car on its side.When I put the wheel back in I had to pull the lever a few time before it went hard, which is fairly normal as the piston could have been moved back whilst taking the wheel out. But the other day on very bumpy down hill the lever went to the bar, I did the run again 3 times and everytime on teh same drop it went to the bar!
Maybe it has something to do with the fuild level in the lever. Anyway I have now bleed it and cleaned the pistons, we will see what happens.
Hi all, I had the same issue and sent them back to the online retailer who in turn sent them back to Madison/shimano. the seals on the piston in the lever were dodgy so would release the brake pressure a few seconds after pulling the lever.
They were replaced within two weeks, so I think Madison/shimano know the brakes are poorly manufactured.
The term mineral oil is like engine oil. Loads of different component mixtures, for example cyclo mineral oil is definitely thicker than shimano fluid. In that article on the first page im pretty sure there's a table with a boil point temps on it and shimano claim their BP is a lot high than bog standard mineral oil or even royal blood.
Is it just this/last years Shimano brakes that do this?
Are deore brakes problematic?
I have some Avids that I was going to swap for Shimano...
I have my Hope X2's for sale because I wanted to buy some M8000's.
I've never had a bad set of Shimanos and I've had few sets of Deore/Slx.
Think I'll keep my Hopes now though because aside from the length or shape of the lever they're ok for me and my riding.
I have SLX and no issues, the XTs are not the same. For all those that insist on saying it must be the bleed etc, do be brief - i do nothing different between the slx and xt yet the XTs are so inconsistent they are dangerous. They have gone back to Madison. The latest mbr also refers to inconsistent bite point for a set of XTRs, something is wrong somewhere.
I've had a few sets of Shimano brakes and have generally found it easier to get a good bleed out of my Deore's over the posher ones. My XT's were powerful but I was never ever able to get a good solid lever feel and not where the shop I bought them from. My Zee's are easy to get set up well and seem consistent as we're both pars of Deore brakes that I had. My current XTR's may well be going back because they were pretty inconsistent on Saturday.
I think the new bleed process is more of a ball ache than it was on the early Shimano brakes. They were so easy to bleed and my original Saint brakes always felt great.
How many people are getting filthy black contaminated mineral oil out when they bleed?
When I have had this, it's usually coincided with the onset of inconsistent lever feel.
I can only speculate that this is from a seal that's deteriorated.
As it's evident at the lever end, I suspect it's the piston seal in the lever.
How many people are getting filthy black contaminated mineral oil out when they bleed?
When I have had this, it's usually coincided with the onset of inconsistent lever feel.
I can only speculate that this is from a seal that's deteriorated.
As it's evident at the lever end, I suspect it's the piston seal in the lever.
Yep - totally black after just a few weeks - although I'm voting for caliper seal
sorry to resurrect this thread, but after boldly claiming mine only do this when the pads are soon to die, the rear has been doing on newish pads on every ride for the past couple of weeks, creating a near death moment at wharncliffe today.
the consensus seemed to be that it was mainly a rear bake problem and likely due to the pistons not auto adjusting due to the seals. has anyone swapped a previously dodgy rear caliper with a working fine front caliper on their bike to see if it is a rear specific or a dodgy unit issue?
just trying to eliminate possibilities before i buy a new caliper (will do my usual overfill bleed first, but as that what was done last time not holding out much hope)
Don't know, but that would certainly narrow it down to lever or caliper sofaboy, 2 year warranty you know?
Don't know, but that would certainly narrow it down to lever or caliper sofaboy, 2 year warranty you know?
weren't bought as a complete set. currently saint levers on zee calipers (both under 2 years old) as smashed up the original zee lever assembly in a crash. not sure they would warranty a hyrbid set up, further complicated as bought from different online retailers. frustratingly i can't remember if the original full zee set up suffered from the same issue
very keen to sort out as today was very close to a face tree interface
I have been meaning to swap my front and rear calipers round to see if that moves the problem to the front, but haven't had a chance yet. I have also been meaning to try and send the back off for a warranty job, but that would leave me without a brake, which, as bad as the brake is, it's better than nothing. I could borrow my wife's back brake (xt working fine) but she might notice.
I did try over filling the system, which was fine for a while, but muddy sandy riding meant it wasn't long before enough pad had worn down to bring me back to square one again.
What a pain this all is.
tombon - Member
I have been meaning to swap my front and rear calipers round to see if that moves the problem to the front, but haven't had a chance yet.
if you do, let us know how you get on. i was going to do it myself, but the waters have been muddied by having a hybrid set up (saint levers, zee calipers) and i can't remember what the original set up (zee's at each end of the hose) was like
I've had a set warranted full of green Citroen mineral oil.
Fed up with my rear XT and dropping wheel out to pump pistons out to allow for pad wear! Tried bleeding but still comes back. Just ordered Hope E4s last night!
So far, fingers crossed, my new XT M8000's have been rock solid. Only one ride on them mind...
I had to shorten both font and rear hoses, pumped the pistons out before I did it.
Currently very good and solid but we'll see innit.
For what its worth i have just blead up the rear brake on a Kona process (third time lucky)and seem to have got a much better lever, I put the bike in a upright position so that the lever is at the top and caliper directly below,then i fitted a rockshok blead kit syringe (with o ring) into the lever/resevoir, Yes they fit!,After a while,and by tapping on the hose and moving the lever up and down on the bar small bubbles started to flow into the syringe followed by a bigger one.The lever felt much better straight away,having the rubber O ring on the resevoir is key here as its a visual guide to releasing trapped air.
Try a bit of logic. If it is mostly a problem with rear brakes then you can eliminate anything which front and rear brakes have in common otherwise it would effect both equally. As far as I understand it most of the equipment (seals etc) front and rear is the same. Do rear brakes get more crap and contaminants than front? Possibly but is that enough to account for the difference frequency of rear brake compared to front. It seems to me that the biggest difference is in the length of the hoses and, if brakes are bled in situ, the more horizontal run of the rear compared to the more vertical run of the front and maybe the orientation of the calliper. So orienting the bike so the rear hose is as vertical as possible (or removing to do the same) and giving it all a good tapping is likely to be a good plan. I've never had a problem with XT on two bikes doing this.
I had some XT M8000s. My front was worse than the rear - even from new before hoses were shortened. I bled about 5 times (with Shimano oil) including leaving overnight with lever tied back to bar etc...none of it worked. Have older shimano's on our other bikes which have been bulletproof. Madison warrantied...got a refund ... now have Hopes which are spot on.
Shame...been Shimano fan for over 20 years...hey ho.
Solved my issue finally; replaced them 😆
XT 8000's still rock solid...
While my XT braked bike was in the LBS having it's suspension service I let them do a full bleed on them and explained the issue. Came back bob on. I was really impressed. Still not quite as firm as the SLX set (that haven't had a bleed in 1000+ miles and 16 months of use) but not far off.
Two or three rides later... the XTs are starting to feel less firm already.
I think if I didn't have the SLX to compare to I'd not bother but I do...
I replaced the pads and rotor like i mentioned earlier, had one ride where everything was super tight and cool and like new. Then back to spongy crappy braking that pumped up. Only thing i havent replaced is the caliper and hose now so they're my next targets. I suspect there's a leak somewhere.
Jack.
Just had to bleed both my new xt m8000s.
I already did the rear two weeks ago and the bike has only been out once since.
Brakes were both spongy and could be pulled to the bar. I think they may be going back as I've only had them a few weeks 👿
Bled mine to the letter of the law with an Epic kit this time, stayed good for 2-3 weeks (a record)! Then I had to have 3 weeks off, now back to shit again
Chipbutty - Member
Fed up with my rear XT and dropping wheel out to pump pistons out to allow for pad wear! Tried bleeding but still comes back. Just ordered Hope E4s last night!
Pretty much how I remidied the issue! And Shimano/Madison still refuse to acknowledge there is an issue even after 5 pages on this thread alone!!
Posted about this on another thread, I had XT M8000's on both my FS and HT but experienced either a lack of modulation or low modulation, so one minute the levers are touching the grips the next the the slightest touch locks the brakes on both sets. Despite regular bleeds I gave up on the FS and fitted SRAM Guides RSC's, a revelation so far, will probably look to swap-out the XT's on my HT as funds become available.
This has happened twoice on my rear XT. My LBS told me that the levers will eventually fail, after months of harsh peak district riding. When they went to replace the hose, they told me it couldnt be done due to the lever being corroded inside. So I replaced the unit and the same thing has happened again. The lever pulls all the way back to the bar, even after a full bleed.
I'm going back to my cheaper more reliable Deores.
Noticed a nice coating of oil on the linkage and behind the lever blade on both my SLXs at the weekend. Looking forward to the master cylinder completely giving up (again, the rear is a warranty replacement)
I'm on my second set doing this and going to swap the calliper around replacing the front with a spare Saint and putting the "good" front XT on the rear. Will let you know how they go
Question for people, how are you all storing your bikes? My last one died after a trip to wales and putting the bike upside down in a van. The new one has died since i moved house and store the bike by hanging it on the front wheel in the garage.
my gut feeling is that Shimano brakes like to be kept the right way up at all times.
Mine hang up by front or rear wheel alternately.
On two wheels, so always the right way up.
Mine is definitely the rear calliper, the inner pad doesn't make full contact with the disc. Same has happened to several people i know, all with XT's.
i've swapped out to my brand new spare set of brakes (Formula CR1's) which depending on what you read will be awesome and last for ever or will kill me in seconds.
Ive just bought some XT M8000's. Now thinking about sending them back after this thread. Question is what is the alternative for good solid XC brakes then? Ive had XO's in the past and they were pretty good for me despite some shocking reviews. Other thoughts?