Unknown brake noise

[Darron1117]

Hello Rocketeers,
Changed out my rear brake pads today and everything seemed to go fine. Pads went in with no
problem and was very easy to do. Once I finished, I sat on the bike and rolled it a bit and hit the
rear brake and it felt like it always did and seemed fine. When I applied the rear brake I hear a single
tap that sounds like hitting a door or a wall with a single knuckle. Not loud, but is heard. If I push the
backwards and apply rear it does it too. Haven't ridden it yet. Didn't do this before changing the pads.
Did I jack up something?
Thanks in advance.

 

[mr hunt]

It could be the disc 'floating' back and forth on the buttons that lock it to the carrier

 

[R-III-R Turbo]

It could be the disc 'floating' back and forth on the buttons that lock it to the carrier

Hmm the rear brake disc is fixed, and the calipers floats (front brakes are the opposite). But the noise could indeed come from caliper movement.

@Darron1117 have you eyeballed the brake caliper & pads while pressing the pedal, to see if you can spot what causes the noise?
Take a pic or better still a video for us too.

 

[mr hunt]

Hmm the rear brake disc is fixed, and the calipers floats (front brakes are the opposite). But the noise could indeed come from caliper movement.

@Darron1117 have you eyeballed the brake caliper & pads while pressing the pedal, to see if you can spot what causes the noise?
Take a pic or better still a video for us too.

He only mentioned rear brake twice....how am I supposed properly comprehend the question

 

[Darron1117]

Hmm the rear brake disc is fixed, and the calipers floats (front brakes are the opposite). But the noise could indeed come from caliper movement.

@Darron1117 have you eyeballed the brake caliper & pads while pressing the pedal, to see if you can spot what causes the noise?
Take a pic or better still a video for us too.

It only makes the noise if the bike is rolling. No sound at all if I apply rear brake sitting still.

 

[Darron1117]

Hmm the rear brake disc is fixed, and the calipers floats (front brakes are the opposite). But the noise could indeed come from caliper movement.

@Darron1117 have you eyeballed the brake caliper & pads while pressing the pedal, to see if you can spot what causes the noise?
Take a pic or better still a video for us too.

I will take photos. There's no play at all. Caliper is solid. The inside pad wiggles just a little bit.

 

[R-III-R Turbo]

It only makes the noise if the bike is rolling. No sound at all if I apply rear brake sitting still.

That would indicate that the noise is from circumferential or radial movement (e.g. torque reaction bolt) rather than axial.. but there are too many factors to jump to that conclusion.
A good video will greatly help

 

[1K9]

Try... remove the pads, loosen everything. Exercise the pedal and expose some of the pistons. Are the pistons clean? If you have never done a deep clean of the caliper and pistons, this is a good time. Clean well with a tooth brush, brake fluid and brake cleaner. Simple Green and flush with water well. Use gloves. That brake cleaner looks carcinogenic. Do not contaminate the disc or pads. Seat pistons as far as they will go, reinsert the pads. Apply pressure to the pedal so that the pads grab the disc. Apply final torque while the pads hold the disc. Roll the bike. If it's still doing it, lift the bike and try rolling the tyre. If that don't do it, I have no idea what it could be.

 

[Darron1117]

Try... remove the pads, loosen everything. Exercise the pedal and expose some of the pistons. Are the pistons clean? If you have never done a deep clean of the caliper and pistons, this is a good time. Clean well with a tooth brush, brake fluid and brake cleaner. Simple Green and flush with water well. Use gloves. That brake cleaner looks carcinogenic. Do not contaminate the disc or pads. Seat pistons as far as they will go, reinsert the pads. Apply pressure to the pedal so that the pads grab the disc. Apply final torque while the pads hold the disc. Roll the bike. If it's still doing it, lift the bike and try rolling the tyre. If that don't do it, I have no idea what it could be.

Thanks, will do. A little cold in the city, today.

 

[1K9]

Thanks, will do. A little cold in the city, today.

Where in Houston are you? I' near NASA Johnson Space Centre.