Whats wrong with my rear brake?

[Gonzo]

I run deore discs with a 6" rotor on the back and the problem is that when it gets heated up it starts squealing and then if i pull on the brake harder the frame starts to vibrate. Im not sure whether the caliper is aligned improperly or what. Whats wrong and how do I fix it.

my hayes hydro does this but i think its because when i lock on hard the tread on my tyre is doing it not to sure though

[kalem]

check everything is tight, i'm sure it probably is, but getting the disc tabs faced so they are properly aligned might solve the problem...

[sxereturn]

We had a bike in at work the other day, for a new tire and tube. Like most other bike mechanics, you usually run over the whole bike real quick to make sure there's nothing horendously wrong with it. I spun this guys back wheel, and grabbed his back brake (XSIV hydro) and this super loud screeching noise came out of it.

The caliper bolts were less than half done up...

It's amazing how people can own bikes worth $1000's of dollars and not know even the most basic things about them.

[lupine128]

realy obscure one for you.
check and make sure the pad tension sping (the little spring that hold the pads apart) is in place, and not stuffed. that can often be the cause of squeal as well.
on a more regular note, check that all is tight; check the caliper is properly spaced so that it is sitting the right distance from the disc, and central to the disc; check that the pads are worn evenly, that they aren't more worn at the front or the back (shows that the caliper isn't square); and check that the bolts on the rotor are properly tightened.
if it still does it after all that, someone else wil give you more ideas.

[Gonzo]

Ok thanks all, ill have a quick look over all that