Disc brakes Shrieking - need new pads?

Fian

For the last week or so my disc brakes are shrieking, though the noise stops after i have used them 2/3 times.

I haven't really noticed any reduction in braking power.

Does this mean the pads are wearing out or is it just because of the cold maybe? I have a feeling that because it disappears when i have used them a few times it is probably just that they are cold?

arybvtcw0eolkf

You might have a build up of brake dust behind the pads, in which case just drop the pads and dust the calipers with a soft brush (pint brush is ideal). You can buy a can/spray of brake cleaner but that's probably overkill for bicycle brakes.

If that's beyond your ability try blowing your brakes with a tyre airline/compressor at your local filling station.

Worn brake pads will usually show up as a rough grinding sound, and sometimes you'll feel it through the bars.

Finally you should be able to visually inspect your brake pad wear without dismantling your brakes.

Youtube is your friend too

Lemming

Some additional maintenance reading if the issue persists: Silence That Squeaky Disc Brake

Viper_JB

Caliper might be slightly out of alignment if it keeps on happening - there are two bolts that attach the caliper to the frame - if I'm getting a disk rubbing constantly what I do is loosen up the bolts - spin the wheel a bit and then hold the brake lever, or ideally get someone else to hold the lever for you then slowly tighten the bolts back up - when they start getting any bit tight alternate between them doing 1/4 turn each so you don't misalign the caliper while tightening, might take a couple of goes to get perfect but most of the time this solves the problem for me - definitely something worth a try and nice a fast fix also.

Koobcam

Best thing to do would be to take out the pads and have a look. In most cases, this just means taking out a bolt or clip that holds the pads in place and popping them out. It's easy to tell if the pads are worn-basically, the pad should protrude from the metal plate that its attached to, there should be at least 1mm of pad material. If the pad material looks worn beyond this, probably best to replace. The noise could also be due to some cleaning product used on the brakes. You can also try cleaning the pads-I think something like white spirit is ok to use.

Lumen

I found this useful.

http://www.mtbtips.com/how-to-fix-squeaky-disc-brakes-on-a-mountain-bike/

My very new discs squeal in the wet, but a bit of hard braking sorts it out. It's just difficult as a roadie to get my head around the concept of slamming on the brakes after years of braking as little as possible to preserve my rims.

JBokeh

Is it a road bike or MTB? I had brakes on one of my bikes that didn't really bite until they were dragged on a bit,and a bit of heat got into them,they had the metal sintered pads,they always made a bit of a turkey gobble sound too. Especially the first few times you used them

Current MTB has brakes that make a bit of a scratch when first applied,but it goes away,often times it is because of mud after building up in the pads.

Best thing to do is get some automotive brake cleaner and take the wheel off,spray the cleaner onto a rag and give the disc a good cleaning,do the same with the pads,and try to get them to go back in on the same sides they came from,it makes them easier to bed in I find. Allign the calliper to the disc by looking down through it and getting the gap between the pads and the disc the same on both sides,tighten the calliper up carefully then to avoid dislodging it

Then go outside and do a few repeated stops from 20k to nothing,but don't come to a complete stop,get going again and repeat until brake performance is good again. I find spraying a small bit of water over the calliper helps a bit here as it clears any of the residual muck away. Don't put it on the disc when it is scorching as it could warp it