Shimano M486 hydraulic disc

[Gimp]

Posted this in the Shed but might be some people in the MTB section who are more knowledgeable on this .............

"Hi All
I have a noise coming from my front disc brake thats almost a vibration of one of the pads against the disc when travelling at speed.
Brakes are Shimano M486 hydraulic disc - looks like one of the pads does not release away from the disc as far as the other side
Does not seem to effect the bike but bloody annoying - anyone else had similar problems or any advice (and no - ipod is not a solution..... )"

i might have depressed the brake handle without the wheel being on during transit but unsure - would this create problems?

[trailgumby]

Depending on your riding environment, they will often need periodic disassembly and cleaning, and occasionally the caliper will need disassembly and cleaning and while your there, the o-rings and seals in the caliper should be replaced.

When you think about it, the trail is a pretty hostile environment - fine dust and dirt gets everywhere, and if damp it can set like cement when it dries out.

The good news is bleeding the system is actually pretty easy if you follow the procedure as they describe it. YOu just need the service kit from your local bike shop.

[scotto]

could be poor adjustment, a piston/pad not returning / rotor slightly warped.
1. check adjustment - loosen bolts holding caliper, squueze brake tight, and tie on with cable tie/string etc , tighten caliper bolts
2. clean out. i use a brake cleaning aerosol, but the label says be careful of painted surfaces. otherwise rebuild or LBS
3. visual inspection. swap with rear and check ?

[Chanboy]

This is a pretty common problem - I've had something similar at least twice.

One time easily fixed with a "caliper re-centre" - Point 1 of scotto's post. (though I usually skip the cable tie part)

The other time fixed when I replaced the pads... the separating spring had gone soft and wasn't pushing the pads apart.

[Comedian]

My hybrid has barely 3k on it and both ends have required cleaning.

I'm a little disappointed with this.

[Nobody]

This might help:
http://www.mtbr.com/discbrakesfaqcrx.aspx

[zero]

My hybrid has barely 3k on it and both ends have required cleaning.

I'm a little disappointed with this.

It took < 50kms of light rain riding to destroy a set of rim pads on my roadie. 3k is a reasonable brake maintenance interval

At ~24,000 kms / 4 years of all sorts of usage (including a race and quite a bit of offroad, and lots of wet commuting).
I have a similar problem as the OP on my front - though both my pistons do retract. My rotors are thinned and have a detectable groove edge below the pad swept area.

Have new rotors on the way. Will see how it goes cleaned with new pads/rotors/fresh oil, pistons worked a few times through their range, but in hindsight suspect it would need new seals too. At the moment, the whole caliper is $30 in the UK - wish I tagged one onto my last order in all honesty.