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Discussion Starter · #1 ·
OK so I finally got a set of XTR trail brakes last week when the Martas kicked the bucket for the X'th time. A few observations: I've never had actual "one finger" brakes before. It's really quite amazing. To be able to descend absolutely anything with the confidence of 3 fingers on the grips and only one on the levers. Power beyond anything I've experienced in 15 years or so of mountain biking.

Here's the thing though. They get hot, then they get loud. Now I've had loud brakes before (XT V brakes anyone?) and I know there's threads all over here talking about turkey gorble, vibrations, and squeeling but my back brake gives new meaning to the words noisy brakes. The sound is actually deafening. I've been around jet and turboprop engines and the noise my back wheel makes puts F-18 hornets to shame. They kind of sound like a Hawker 748 at idle but louder.

I have Marta 160 mm rotors still is that the problem? Is it a contamination issue? I did puncture a tire on the non drive side and spill some Stans. Could that have contaminated things in such a way as to only be a problem when things heat up? The front brake has a 170mm marta rotor no sound. Am I the only one to experience this?
 

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Must be your rotors, most reviews of this brake show a quiet brake. I have the same brake and XT Ice 6 bolt rotor and its super quiet.
 

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Discussion Starter · #4 ·
Thanks guys. I just bought a 6 bolt XT Ice Tech rotor and I also bought some Resin pads. Weird but the stock ones were metallic. Last time I ran Shimano brakes was XT's in 08. I found the resin significantly quieter especially when wet but they didn't last as long.

The 170 mm Marta rotor on the front is new this summer so I think I'll run it for a while and see how it goes. To switch to shimano I have to choose between 160 and 180 mm and thus buy a new adapter.
 

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You've got an old rear rotor with all the grooves in it from all the time in use with the Magura brakes, plus likely a different pad compound ground into the grooves, so you will have some period of time to re-bed the rear rotor in fully. In that process you may glaze the XTR pad or it may just take some time to wear the matching grooves into the pad surface.

The caliper might not be aligned 100% parallel to the rotor as well, that really creates a howler situation.

The ICETech rotors make a huge difference, it's worth upgrading to the new rotors.
 

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Discussion Starter · #6 ·
Done! Will find out in a few hours if that fixed it. Gonna keep the stock metal pads on to see if the noise goes away. I sanded them down with wet 200 grit then dried them with a blow torch just to get a nice new layer exposed in case contamination was an issue.
 

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Check your XTR caliper, while out riding my front brakes started making noise .....then lost power....not like this new generation XTR.....on inspection there appears to be a leak from the LH piston, which has seaped down onto the pad....damn they're only 6 rides old.

I thought I'd got away from leaky brakes ie. Hopes
 

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Update......

Looked over the brake further and also found that the hose was leaking from the alloy furel (sp)...looks like the factory crimp wasn't good enough....

This has also allowed disc brake fluid to seep down over the caliper towards the pad.

Did a total clean of the rotor 3 times with an automotive aerosol cleaner and also did the same to the pads and roughed them up with emory paper.......and replaced the brake hose, as I there was no way to fix the factory crimp....grrrr

Bled and rode......naturally (unfortunately) the pads are toast and the shimano rotor (out half) has taken on a hue of darkness where the brake pad effected by the brake fluid.....hence it's lost it's power...damn!

When I got home I pulled the caliper and brake pads out to see some disc fluid on the back of the pad.....what next?

I'm going to inspect the rear brake to see if it has the same leak around the pistons along with my other bike with XTR....

Pending the inspections, I may install a fresh rotor and pads and monitor carefully....

The Hope brakes I've used over the past several years were prone to the same minimal weep from the pistons......
 

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Discussion Starter · #9 ·
Well so far I got lucky and the XT Ice rotor made the sound go away. I'm really not sure now what the problem really was. If I've had contamination problems before but contaminated brakes make noise when they're hot or cold.

My new XTR's only made noise when hot, and only the rear one with the old style marta rotor. Apparently Magura changed their rotor design last season in response to failure issues.

In 07 I bought the old version of XT brakes and the rear one had to be bled every week and would constantly squeel. It must have been fluid getting past the seals on the callipers (like your problem) but I could not get a warranty. In fact my LBS sent the brake to shimano for a warranty and they returned with a nasty note to the tech saying that all they needed was a bleed and not to bug them with trivial stuff like this... 2 rides later the problem came back.

Don't give up on your issue and get your LBS involved. Mass produced parts don't always work properly and manufacturers will back them up eventually if you're persistent.
 

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hey gripo

sounds like exactly the same issue i had w my 2012 xtr front - all of a sudden - noise - and no power - and there seemed some oily residue on caliper - but must have leaked during a long descent - dont see any leakage after i wiped it off

sanded pads and rotor and nothing helped - you ended up replacing hose? new pad and rotor?

any advice appreciated

simon
 

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hey gripo

sounds like exactly the same issue i had w my 2012 xtr front - all of a sudden - noise - and no power - and there seemed some oily residue on caliper - but must have leaked during a long descent - dont see any leakage after i wiped it off

sanded pads and rotor and nothing helped - you ended up replacing hose? new pad and rotor?

any advice appreciated

simon
yes, all 3.......had spare pads/rotor......had to buy a new hose, the alloy banjo was leaking from on top of the alloy furle (sp)....after wiping you could see the brake fluid fill the crimp when squeezing the front brake lever...
 

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thanks

hey gripo - thanks for your help -

so pissed at shimano - called them - and they were NOT helpful -
i clearly have a faulty brand new XTR disc brake - maybe 20 rides on it - and a leaky hose forces me to buy pads, rotor and hose - that is crap!
 

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yes, all 3.......had spare pads/rotor......had to buy a new hose, the alloy banjo was leaking from on top of the alloy furle (sp)....after wiping you could see the brake fluid fill the crimp when squeezing the front brake lever...
Couldn't you have just bought a new compression olive and use the old fittings? You will most probably just have to shorten your hose by about 10-15mm to get rid of the part of the hose where the old olive had actually crimped the hose ... :skep:

Let me correct myself above ... had a check and it seems you have to buy a new hose, if you decide to stick with Shimano ... dang!!! ... Sorry I use after market hoses and fittings and just assumed that all you needed were new olives.
 

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Hi, same problem here. Noise and no power at front brake. No leakage visible... replaced pads and cleaned rotor. After summer holiday no repeat of the problem. Strange...
 

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noisy XTR brake - no power

i had to look very closely to see the leak by the crimp - it only happens slowly - and under lot of pressure - but thats exactly what happened - oil from leak at crimp made it to pads - and ruined pads - overnight this brake went from amazing to complete rubbish
 

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Warning to all......just had a look at my bike with 2012 XT's (F/R) and they also have the same fault with leakage from the crimp on ths banjo/caliper end...

This looks to be a wide spread fault with the BH90 series hose....watch'm.
 

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Damn.... Same here....

After only 2 rides my front 2011 XTR front brake lost power & started squealing, upon inspection I noticed some brake fluid on the caliper & brake pad. I tried to clean the pads but nothing has helped much.
The rear seems ok for now.
I will check the banjo for leaks.

New pads aren't available yet & will cost about $45, $40 for the hose + shipping.

Shimano should replace the hoses & contaminated pads.
 

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Has anybody called Shimano about this? No way in hell did I just drop $500+ on new brakes and am going to pay for a new hose and pads. I need to look at my XTR's more closely.
 

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Mine is weaping like a goodun. CRC said send them back and we will send them for repair! I can order a hose and connector/olive for £30 and still have my bike early next week. If i return them it could be ages and i end up with no bike.
 
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