Noisy hydraulic Shimano disc brakes. Honk!

rich_p

I’ve been using my new bike for a few weeks now and the brakes have been silent. The rear made more of a rubbing sound than the front but no squeaking at all.
I hosed the bike down last week and on the next ride the brakes began to squeak/honk.

I took it out last night and made a few high speed stops which has shut them up, apart from when coming the final stop – then then make a loud honk!

The rear brake is louder and if you brake heavily over grass for example it will do the honk sound a couple of times, almost as if it’s juddering and doesn’t really lock up as you’d expect if you are hard on the brakes.

Could this be down to the calliper going out of alignment?

I’m convinced the braking power isn’t what it was before either and both brakes seem softer. (only change I’ve made is moving them inboard on the handle bars.)

Does it just sound like the pads need taking out and cleaning, along with the discs? Would contaminated pads cause the lack of bite?

There aren’t any leaks on the brakes, can general muck from the frame run onto the brakes while the bike is being cleaned?

The Rookie

When you hosed it down, just water or ANYTHING else?

rich_p

Just plane old water at the jetwash.

nicklouse

Rich_p wrote:

Just plane old water at the jetwash.

so you used what ever was left in the system..... most likely wax.

new pads and clean the rotors.

rich_p

Doh,

That very same thing just occured to me moments before you posted!

Thanks.

rich_p

Do you think I can get away with soaking the pads in brake cleaner and sanding the surface of them to bring them back to life?

nicklouse

i would just get new and clean the rotors and using a jet wash has never ever been a good idea.

The Rookie

As Nick says, Jetwashes are a bad idea, water gets past the bearing seals under the pressure, tap, bucket, sponge!

DannyJames

I lightly sanded my pads and discs then cleaned them up with electrical cleaner spray from Maplins ( Isopr???) anyway this was on contaminated avids that were so noisy i would not ride it and it cured it cost about a fiver

Usefull guide http://www.pinkbike.com/news/Tech-Tuesday-Silence-That-Squeaky-Disc-Brake-2011.html

The Rookie

Contamination isn't the only cause of noise......squeals are not usually contamination, the honk associated with a juddery stop is.

That Article is written by a chap from Avid who funnily enough neglects to mention that one of the biggest sources of squeals with Avid brakes is due to the rubbish flexi mounting system they use......