[Closed] Disk brakes squealing like pigs

clean the discs with methylated spirits.

Mike,

Get some copperslip. I had the same issue with my Avids and tried all sorts of cleaning and filing to no avail. I bought a tube of copperslip from a car shop and it went away immediately.

Dogsby

Probably best to mention you want to put the copperslip on the back of the pads 😛

Also, you could try kevlar/organic pads if all else fails.

Probably best to mention you want to put the copperslip on the back of the pads

Just a dab too. If the back is swimming it the stuff, it will find its way onto the pads when it gets nice and hot.

My brakes suffer from this real bad - tried cleaning then with acetone and exposing a new surface but it did bugger all. I'll certainly give the copperslip a go.

And DO NOT use methylated spirits, use alcohol.

Undo the caliper bolts very slightly, nip them up but not tight so they can float/move a bit and ride for a few hours, then do them up tight. Always works for me, absolutely no idea why. Failing that do this

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

joolsburger - Member
Undo the caliper bolts very slightly, nip them up but not tight so they can float/move a bit and ride for a few hours, then do them up tight. Always works for me, absolutely no idea why. Failing that do this

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

After reading that I'd put money on it being cleaning fluid like muck off making mine squeal, I always give a good squirt into the caliper when I clean the bike. Well, I used to...

And DO NOT use methylated spirits, use alcohol.

Methylated spirit is usually 90% ethanol/10% methanol, so [b]is[/b] alcohol...

And DO NOT use methylated spirits, use alcohol.

True dat

Methylated spirit is usually 90% ethanol/10% methanol, so is alcohol...

Plus various other potential additives (such as mineral oil) which leave a greasy residue making it totally unsuitable for cleaning brake rotors.

Thanks chaps 🙂

If you are cleaning your rotors you want Isopropyl Alcohol. I recently got [url= http://www.amazon.co.uk/AF-International-Isopropyl-Alcohol-Cleaning/dp/B000WGTZ6M/ref=sr_1_1?ie=UTF8&qid=1396254208&sr=8-1&keywords=Isopropyl ]some in a pump spray from Amazon[/url].

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It's a bit dearer than the regular bottles, but convenience + free delivery, and not having to root around the shops trying to find it, makes it worth it for me.

I'd check rotor bolts too. A bit of corrosion there could lead to loosening.

Brake squeal is caused by vibration which is often due to uneven pad material on the rotors. Sand the rotor surface to remove all existing pad material and then clean with IPA alcohol and a clean rag (not meths) and lightly sand the pads keeping them flat although if they're contaminated then it's best just to use new pads. Makes sure the calipers are aligned evenly and straight to the rotors and the all bolts are tight then bed the pads in properly to put an even layer of pad material on the rotors by doing 20ish hard brakings without locking up or coming to a complete stop.

Don't put any copperslip or grease on the back of the pads as it's doesn't stop the noise, can damage the caliper seals and risks contaminating the pads/rotors.

Never had a problem with meths myself, but then again, my bike is usually a candidate for grubbiest of the the year on most days, so make of that what you will! 😀

I struggled with this, and even posted a similar thread on here but mine was 'like a herd of elephants'.

In the end I just got some Muc-off disc break cleaner. I spray the pads and rotors after every big ride once the bike is clean / dry (usually the morning before my next ride), or after every 2-3 local rides. They are now pretty much silent.

N.B they're Avid Elixir 3 brakes.