Philadelphia Mountain Biking Association - Forums

scott again i was out today at pennypack and my front and rear disk brakes will not stop squeaking only when i use them can you guys help me with this please

The first thing I would do is remove the pads and clean them with rubbing alcohol, also the rotors. If hydraulic do *NOT* squeeze the levers with the pads/wheels out or you'll have some work to do. Not that I've accidentally done that or anything. I've also heard of people sanding the pads if they've gotten glazed, but I would try just cleaning first.

-pete

Good ideas Pete. What kind of brakes do you have? Some of the pads are tricky to get out, but the manual will have good instructions. You can also do this with the wheel on. Clean your hands and get a brand new rag with nothing on it and wet it with rubbing alcohol. Squeeze the rotor with the rag between your fingers on both sides, and spin the wheel. Watch all the black crap rub into the rag. Next squeeze the brakes lightly so it drags on the disc and spin the wheel around once or twice. This will scrape alcohol onto the pads. repeat step one until there is barely any dirt coming off the rotor... If this doesn't work get new pads (organic) They are cheap and make a big difference. You shouldn't pay more than $15 (more like $10) for each set. Good luck...

P.S. never touch the rotor braking surface or pads with your fingers...

Also keep in mind that if your pads do become comtaminated by the brake fluid they are shot and need to be replaced. I had a leaky piston one time that smoked a brand new set of pads.

Might be something as simple as slight rubbing caused by the rotor not being centered inthe caliper perfectly or pads not retracting all the way.
Sometimes something as simple as poping the wheels out, re-seating them in the dropouts nicely and tightening the QRs well, does the trick of stopping the rotors of grazing the pads and stopping the squack.

I always try fixing problems by applying the cheapets/easiest solutions first. Like my boss says, address the lowest hanging fruit first.

Good luck

dz

What brakeset?  The calipers and rotors may not be square to each other.  This is most frequent with IS tabs as opposed to post mounts.  Take a look at the rotor in the caliper and check that they are parallel to each other.  If they aren't, take Dmitri's advice and make sure the hub is tight in the dropouts.  If they still aren't square, hopefully you have avids - loosen up the caliper mounting bolts a good bit, jostle and twist the conical washers, make sure the fixed pad is where you want it to be, turn the outboard pad adjuster till the rotors pinched in the pads and tighten the bolts down - if it's avid hydro, follow the above steps and once everything's loose, squeeze the levers and tighten the bolts. 
If it's not avid, the tabs need to be milled square - could be poor welding, excess paint, etc.  A good shop has a disc brake tab milling device.
Make sure all bolts (don't forget the rotor) are torqued to proper spec - 80 inch pounds for most caliper and adapter bolts and either 55 (everyone other than shimano) or 35 (shimano) inch pounds for the rotor bolts.