2011 XT Brake Issues
So I invested in the 2011 XT Trail Brakes. I LOVE them...well pretty much.
The first several hundred miles / months have been awesome. Now though, with still a good few mm of pad (metallics) left, the front brake has started squealing and will not lock up. Even at slow speeds, it squeals and won't lock up. Incidentally, I am also using the ICE tech rotors...180mm so this makes no sense to me.
The lever feels solid...I don't think it needs a bleed. I cleaned the rotors with alcohol as well as taking fine grit to the pads and cleaning them and the pistons gently with alcohol as well.
It's like the pads are not pushing far enough even to really grip the rotor though the lever is solidly maxxed out (no spongy feeling.) So it seems like a pad contact issue. I suppose I will play with the freestroke adjustment but it doesn't seem to do much or have very much range.
My last resort is to just buy new pads but at $40 a pop that's a bummer since these still have a few mm and apparent life left in them. My rear brake...with about as much pad left still rocks.
The local bike shop guy is stumped too. Any thoughts? Suggestions?
Grand Master Jedi
Is there any piece of metal protruding through the pad material from the backing plate? If so, this metal to metal contact could cause squealing and would prevent good brake performance.
Shimano's documentation says you can run the pads all the way down to 0.5mm but I wonder if something is restricting the movemtent of your pads? Check the return spring maybe?
I had pretty much the same issue with my xtr trail brakes. Check the hose crimp at the caliper for leaks. If you search around the net you'll find it's common for the crimp to leak. You can test for leaks by using a zip tie to hold the brake lever tight for a few hours and then looking for oil around the hose crimp. I replaced my hose with jagwire hose and had no more leaks. I'm going to guess you have leaky crimps and your pad probably has oil on it. I was able to fix my brakes and save the pads by burning the oil out of them. Click on the link to see my post about it.
Xtr trail brakes, goodridge replacment hose?
Thank you guys...great suggestions.
Well, here's what I think after messing with it all afternoon. cbusierre, I think you were / are right. First, I cleaned the pads (both front and rear) really good with 91% alcohol and sanded them again lightly with light sandpaper. I swapped the front to the rear and bang...now the rear had the same issue and the front was golden. So, it had to be the pads...and not the thickness, but something in the pad or pads themselves.
I brought them into the shop and they said that there CAN be defective issues with the pads. So, at this point I just bought a new pair ($45 ouch!). I put the "good" worn pair on the back, the new pads on the front and they are once again awesome all around!
So, I think there is / was something wrong with one of those pads...the original one's in the front. Like you said, I suspect a chard of metal that is not wearing uniformly or something like that and the sandpaper I was using was too fine grit to take care of it. I saw some funky marks on my rotor too that would support this theory. So I think I got some junk pads which is a real bummer at $45 but oh well, problem resolved.
Also, I should mention that the shop guys also agree with you on how low you can run them. Despite what Shimano says, they say they may not go as low as the spec...maybe 1mm at thinnest.
So again, at $45 a pop for pads it's a bummer but on the flip side when they are working they are hands down the BEST brakes I've ever ridden.