Lately my brakes have been making a "groaning" noise as I come to a stop. It doesn't do it all the time, only occasionally.
What would cause this? - I think I have plenty of meat left on my pads as they are quite new so I can eliminate that.
Could it possibly be dirt on the rotor?
I am going in for a service in a week so will get them looked at but I am interested in hearing what people think might be the cause of the sound.

 

Not a mechanic but. Most pads are metallic. Metal dust on metal rotors=noise. Can also be caused by dried grease on the back side of the pad. If it was applied at all during install. Cleaning rotor and pads will work for a while but it will return. Based on the materials used for your brake job. IMO

 

Believe it or not my Moco told me that it was normal, but brakes grind as well, but when i apply the front brakes without actually braking the grinding stops....weird but true.

 

Check the pads - may be a rear wheel bearing going bad...

 

I also have a 14 FLHTK and under very light braking, using just the rear brake, I sometimes get a "groaning" noise. This has occurred with each of the 3 sets of brake pads that I have used including the original set. All the pads were stock HD parts and I used the supplied paste when changing the pads. The amount of wear on the pads has not made any difference. I've been changing the pads @ about 20,000 miles when I have the caliper off to do a rear tire change. At times the noise almost sounds like a vibration. It happens most often while braking in parking lots or in stop and go traffic but only under very light braking at slow speeds with the rear brake. Although the bike has the linked braking, it should not have been active at the speeds under 20 MPH. Weather conditions don't seem to affect when it occurs. If you do find the cause of the noise please post it. Thanks.


Edit: I don't think it's a wheel bearing because the noise occurred with the original pads and I changed them at around 20,000 miles. The bike now has 58,000 miles on it and it still has the original wheel bearings. The noise also occurred with the second and third (current) set of pads.

 

Just went through this with new Lyndal brake pads on new rotors. It generally isn't the pads touching the rotors making the noise. It's the pads vibrating (resonance) against the pins and the pistons in the calipers. I used CR Brake Anti Squeal paste on the back of the pads. let it sit for a an hour. Clean carefully and lube the brake pad pins with brake grease. (Lube very lightly. You don't want it to drip on your pads and or rotors) Re-assemble. Should be good. One last thing to look at is if all the pistons are coming out and not sticking.