Squealing brakes driving me crazy!

[boyse7en]

I bought a Cube Ltd Pro a couple of years ago for riding around with the kids.

Pretty much since I had it the front brake has squealed incredibly loudly.

I tried cleaning the pads and disc a few times but it never worked, so eventually i gave in and took it to the LBS and they cited contamination of the pads and fitted new ones.

All was well for a couple of rides (it only gets used a couple of times a month) and then the squealing came back.

Took it back to the LBS who, fair play, fitted a different brand of pads as they said the previous ones sometimes give issues.

Again all was well for two rides, but now the squealing is back again in full force.

I don't know what to do next.

They are Shimano hydraulic discs/calipers. The brakes don't get used a whole lot as most rides are slow ones on flattish terrain, but the back brake is absolutely fine - not a sound.
Any suggestions? It's not contamination, as I haven't done anything maintenance-wise to the bike since the pads were last replaced.
I would bite the bullet and fit a new disc/caliper set if I was fairly sure it would fix the problem.

[Watchman]

What *type* of pads?

I find my sintered pads on my MTB are "screechers" and can be very irritating but they are designed to work in muddy, wet conditions.

My organic/resin pads on my road bike are silent. I much prefer them but I acknowledge why the sintered pads are there on my MTB.

[Mr Gearchange]

As above sintered pads will squeal more. Try either organic compound or kevlar

[richardxjr]

Take pads out and lightly dry sand them to remove any glaze. Disk braking surface also.
Dry clean with a cloth only any crud off the edge of the pads.

Whilst they are out pump out and push back in the calipers a few times (not too far out, few mm), give the caliper pistons a quick whizz and wipe of GT (or preferably some mineral oil) also wipe the rest of the caliper body.

Refit and enjoy.

Edited by richardxjr on Tuesday 19th May 10:28

[Pablo16v]

One possibility is that the front pads haven't been bed-in properly because you're just pootling around.

http://www.pinkbike.com/news/Tech-Tuesday-Silence-...

[Herman Toothrot]

Pablo16v said:

One possibility is that the front pads haven't been bed-in properly because you're just pootling around.

http://www.pinkbike.com/news/Tech-Tuesday-Silence-...

This is on the money, I always do a few rolling stoppies and as hard as almost locking up stops with new pads and my brakes are always silent.

[Bobley]

I've tried all manner of blow torches, nasty chemicals, sandpaper, angle grinders etc to try and silence the howling from the cheap Shimano disks on my Planet X. I swapped them out for Shimano RT86 Ice Tech disks and metalic pads and by jingo it stops now. It still has the occasional moan on first start but a couple of good pulls will shut them up.

Some disks are just rubbish.

[snowdude2910]

Mine sometimes squeal when I first set off and the bike has been sat in the shed for a couple of weeks I just do a few hard stops and it's fine again, I always just presumed it was slight rust build up on the discs like you get on a car that's sat for a while. Never happens if I ride consecutive weekends though bike is a cube stereo with shimano hydraulic discs my mates bikes all squeak on the same rides too as we always ride together which backs up the lack of use theory too. Just ride for a short distance with the front brake dragging or as above do some stoppies/hard braking and it should be reet.