Front brake (Avid Juicy 3) is whining even with no braking force applied

growse · 1 Jun 2014 at 16:19

I got the bike out for the first time this year and riding around noticed that the front brake appears to be rubbing on the disc. This is causing an intermittent, annoying whining sound when riding around.

There's no squealing when I actually brake, the noise disappears then. It's just occasionally when pedalling about. It's almost as if something is flexing against the pad and causing the whine, but I can't think what that could be.

Bike is an Orange P7 with the Fox Vanilla R on the front.

How do I fix it? New pads?

Gribs · 1 Jun 2014 at 17:34

My Avid Elixir 3's did this almost from new and I never got them to be perfectly quiet before getting ****ed off and buying some Hopes. In your case it's likely the piston is sticking slightly if they've not been used for a while. Whilst it may free off with use Shimano Deore brakes are available new for not much more than it'd cost you to pay a shop to sort yours properly and they're pretty much fit and forget, at least until the warranty expires.

Cookeh · 1 Jun 2014 at 17:54

Could simply be its misaligned. Realigning the caliper is a really simple, quick and easy job

growse · 2 Jun 2014 at 16:02

Gribs said:
My Avid Elixir 3's did this almost from new and I never got them to be perfectly quiet before getting ****ed off and buying some Hopes. In your case it's likely the piston is sticking slightly if they've not been used for a while. Whilst it may free off with use Shimano Deore brakes are available new for not much more than it'd cost you to pay a shop to sort yours properly and they're pretty much fit and forget, at least until the warranty expires.

I could just say 'damn it all' and buy some Hopes. I had some Hope minis ages ago, loved them.

Cookeh said:
Could simply be its misaligned. Realigning the caliper is a really simple, quick and easy job

Any pointers how? Not sure I've done that before.

Cookeh · 2 Jun 2014 at 16:42

Slacken the CPS bolts off, spin the wheel, grab a fistful of brake, tighten the bolts up whilst keeping brake on.

neil_g · 2 Jun 2014 at 17:06

guide featuring avid:

hope for one dont recommend the "grab a fistful of brake" technique. afaik all you end up doing is winding your pistons out compounding the problem.

Cookeh · 2 Jun 2014 at 18:02

Its the recommended technique for Avids

Their 'CPS Technology' is designed to align via that method, its in the manuals and all

Cookeh · 2 Jun 2014 at 18:07

Manual here. Pages 8-9. Another source is here.

Not sure why - given completely different designs - you'd bring Hope up in an Avid thread

Gribs · 2 Jun 2014 at 18:18

Avids method may work on new brakes with pistons that are moving perfectly. I didn't for me on new brakes or setting up a mates juicys. The Hope setup method is far better if your brakes aren't in perfect condition.

Cookeh · 2 Jun 2014 at 18:31

I dunno, find that odd really - I've never had an issue with the above on my Elixirs or older Juicy 1s. Its the method the LBS even recommended to me.

tl45 · 2 Jun 2014 at 21:04

Though it's been confined to the shed for maybe a year now I've got the Juicy 3's on my mtb and had similar with the brake noise. Found that pretty regularly I've had to take the pads out then pump the pistons out further, push back in and repeat several times to free the pistons off. Just make sure you clean everything up first, maybe put a bit of brake fluid around the pistons once they're more exposed, and make sure you put something in the caliper to stop the pistons popping out or ending up hard up against each other so you can't push them back in.

The dome/bevel washers for caliper alignment system seem to corrode and can crack after time too.

neil_g · 2 Jun 2014 at 22:13

Cookeh said:
Manual here. Pages 8-9. Another source is here.

Not sure why - given completely different designs - you'd bring Hope up in an Avid thread

Because given hope know their stuff and make much better brakes maybe they'd know what they're taking about.

Or maybe it was just a general observation.

Either way the video offers some good advice. Let's not start a peeing contest.

tl45 · 2 Jun 2014 at 22:17

I've always thought having the name 'Hope' isn't the most confidence inspiring for your brakes...

Would be very apt for road bike rim brakes though :eek:

neil_g · 2 Jun 2014 at 22:21

Neither is "juicy" really

tl45 · 2 Jun 2014 at 23:16

neil_g said:
Neither is "juicy" really

Sometimes apt when you pull the brake levers hard enough for fluid to leak out of the reservoir lid

They were still an improvement on the cable discs brakes my bike originally came with.

growse · 3 Jun 2014 at 00:07

Watched the video, looks fairly straightforward. Will give that a go

tl45 · 3 Jun 2014 at 00:18

In addition to what's covered in the video you can get one piston moving more than the other when you operate the brake - I got in the habit of watching the disc as you operate the brake, then adjusting caliper position accordingly so that when you operate the brake the disc remains central and doesn't flex to one side or the other.

neil_g · 3 Jun 2014 at 08:09

tl45 said:
Sometimes apt when you pull the brake levers hard enough for fluid to leak out of the reservoir lid

They were still an improvement on the cable discs brakes my bike originally came with.

Sounds about right, I think all of my avids had a leaky res of some degree