Brakes are squealing - after new pads installed, rotors cleaned, brakes bled...?

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thisisjosh95

Likes Bikes
So my brakes are squealing and I seriously can't get them silenced. I've replaced the pads (resin pads on resin-only rotors), cleaned the rotors thoroughly and bled the brakes just because they could have used a bit of a touch up. For some reason they are squealing ridiculously. I have roughed up the pads AND the rotors but nothing really seems to work. They are Shimano Deore brakes. Any ideas??
 
pink poodle

pink poodle

気が狂っている男
WD-40 the pads.

All bolts tight?
Pads tight inside caliper?
Pads hitting evenly?
Rotor tight?
You sure the bleed was successful?
You are certain they aren't avids?
 
pharmaboy

pharmaboy

Eats Squid
Um, I'll go for a serious answer.

Have you bedded them in? Amazing things can be achieved with a decent downhill that heats em up, let em cool a bit then go again.

But check all your bolts and that it's nicely centred and even over the rotor.

Next check, pistons going in and out on both sides evenly
 
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thisisjosh95

Likes Bikes
pharmaboy said:
Um, I'll go for a serious answer.

Have you bedded them in? Amazing things can be achieved with a decent downhill that heats em up, let em cool a bit then go again.

But check all your bolts and that it's nicely centred and even over the rotor.

Next check, pistons going in and out on both sides evenly
Click to expand...
have definitely checked all of the above so maybe I guess I should just get it out on the trail and give it a good go? Hopefully a solid run or 10 will get them behaving!
 
The Duckmeister

The Duckmeister

Has a juicy midrange
Cleaning your rotors is a bad idea unless they're covered in oil.

You've removed a nice layer of brake pad material from the rotor surface that's essential for proper performance, so you're really starting from scratch as far as bedding in. Bedding the pads in is only half of it; getting that layer of pad material into the rotor is the other half of bedding in.

Go & pull a few dozen really hard braking efforts, but not coming to a full stop; get 'em warm & really get that surface layer going.

Pro tip: use a heat gun to pre-heat the rotors, but be careful to keep moving the gun over the rotor area & not focus on one spot, otherwise you risk buckling the rotor.
 
pink poodle

pink poodle

気が狂っている男
Cover in metho and set them on fire. Don't use anything oil based (eg petrol) as that will leave residue. The flames with fuck most problems right off.
 
foxpuppet

foxpuppet

Eats Squid
In all seriousness how many people bed in pads and rotors to manufacturers instructions? I did it to the letter on my new brakes and never had an issue..... And yes they are avids
 
DeBloot

DeBloot

Feeling old
See how you go after a few rides
If it's still driving you nuts, get a pair of resin/organic pads and see if it stops

I have never had a problem with turkey gobble using resin pads
In fact my XT's came with sintered pads and started squealing on long descents after a bit of use
I canned them for resin and have never had a problem since
I have done this on every set of brakes for the last 7 years or so and works every time

I find modulation is better and I have never had a problem with longevity either
 
yuley95

yuley95

soft-arse Yuley is on the lifts again
foxpuppet said:
In all seriousness how many people bed in pads and rotors to manufacturers instructions? I did it to the letter on my new brakes and never had an issue..... And yes they are avids
Click to expand...
Me. Never had a problem. Running avids too
 
foxpuppet

foxpuppet

Eats Squid
yuley95 said:
Me. Never had a problem. Running avids too
Click to expand...
Seems to be a wide variety of bedding in procedures people use. It takes about 5-10 minutes to do it right and saves you a hell of a lot of time mucking around with flame throwers, toasters, dishwashing detergent or sandpaper.
 
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thisisjosh95

Likes Bikes
The Duckmeister said:
Cleaning your rotors is a bad idea unless they're covered in oil.

You've removed a nice layer of brake pad material from the rotor surface that's essential for proper performance, so you're really starting from scratch as far as bedding in. Bedding the pads in is only half of it; getting that layer of pad material into the rotor is the other half of bedding in.

Go & pull a few dozen really hard braking efforts, but not coming to a full stop; get 'em warm & really get that surface layer going.

Pro tip: use a heat gun to pre-heat the rotors, but be careful to keep moving the gun over the rotor area & not focus on one spot, otherwise you risk buckling the rotor.
Click to expand...
thank you man I really appreciate that info :)
 
D

DJR

Likes Dirt
I had this happen to my xt brakes. This was after I blew the rear brake hose and got some oil on the pads and also overheated the rotor from the pad rubbing while i rode home with no rear brake.

I tried cleaning everything with brake cleaner, sanded the pads, sanded the rotor, tried to rebed the pads, put antisqueal on the back of the pads. Nothing worked at all, the squeal just came through all the time. Drove me mental. Ended up replacing the rotor and new pads as a set, all good now.

It's not all that bad, I have that rotor and pad set sitting in a box as spares that I will put back on the bike when I lend the bike to someone I don't like :)
 
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