Disc brakes driving me mental!

heathy_76

I need some help before my disc brakes end up in the bin!!!!!!
My pads make an annoying rubbing sound all the time. They're not that new so they should be worn in by now and I've tried all adjustments (they're Shimano so there is that much to adjust really).
When I tried new pads the rubbing noise went but in it's place was something worse. Every time I used my brakes with the new pads there was a juddery feel accompanied with a HUGE sound I can only describe as a cross between a seal and Chewbacca!

Someone please help as it's driving me mental. I can't afford to replace my brakes (as much as I'd like to) and the Mrs is beginning to tire of me disappearing into the shed for hours on end.

howsmyriding27

hmm... a lot of new disc brakes will squeak, and the juddering is just them working, (or you pulling the lever too hard/not hard enough) and i reckon if u just keep using them then the noises should eventually dissappear - my discs used to squeak a lot, but constant use has put an end to that...

heathy_76

Thanks, I'll persevere.
Hopefully it'll sort itself out by next weekend. Otherwise it'll be a bit embarrassing out on the trails when everyone will find out just how much I brake!

Splasher

It sounds like your caliper is not centred.

Jonr

heathy_76 wrote:

I need some help before my disc brakes end up in the bin!!!!!!
My pads make an annoying rubbing sound all the time. They're not that new so they should be worn in by now and I've tried all adjustments (they're Shimano so there is that much to adjust really).
When I tried new pads the rubbing noise went but in it's place was something worse. Every time I used my brakes with the new pads there was a juddery feel accompanied with a HUGE sound I can only describe as a cross between a seal and Chewbacca!

Someone please help as it's driving me mental. I can't afford to replace my brakes (as much as I'd like to) and the Mrs is beginning to tire of me disappearing into the shed for hours on end.

The juddering can sometimes be caused by slight play in the headset or play in the forks, so its good to eliminate those two possiblities before you focus on the brakes themselves.
With regard to the other symptoms I would go with other advice.

heathy_76

The problem is only on the rear brake so that rules out any headset play, but could that mean there's play in the hub??? The juddering/chewbacca sound only happens on new pads, on the old pads I get the rubbing noise. I'm sticking with the new pads for now and hoping that they will bed in and the problem will disappear.

Thanks for all the help.

colbird12

I have a good pdf document "The Rub on Disc breaks" that has lots of causes and fixes to this common problem.

Let me know if you want a copy e mailed. (Been back to the shop 3 times now with my GT Avalanche for this problem)

clipper

it might be caused by the caliper being center aligned to the rotor but not vertically. inspect the rotor to see if the pads are making contact with the "spokes" as well as the intended braking area. if the brakes have been used it will be obvious from the wear caused by pad contact. i've found this can create both juddering and noise due to the surface area used by the pads changing as the rotor spins.

dunker

i managed to replicate the noise you're describing when fitting a 6 bolt rear rotor. i made two mistakes fitting it, firstly i put the little double washer thingys in the inside between rotor/hub rather than bolt/rotor and secondly i did'nt tighten the bolts in the recommended cross pattern. this produced an incredible animalistic howl everytime i braked but once i fitted it properly it's just making the normal shhhhhd or squeel noise depending on rotor temperature and cleanliness?

tmg

Centre your caliper by pushing the pads/pistons back in with flat head screwdriver, undoing the two bolts that hold it to the mount, spin the wheel and applhy brake, whilst still holding the brake tighten bolts