I have an '06 Road King with a TLE sidecar. The disc brake on the sidecar squeals badly. I have taken it to my local Harley dealer five times over the last two years, they have called Harley technical assistance repeatedly and the problem has not been solved. The pad has been chamfered, and of course the anti-squeal stuff has been applied to the back of the pad.

 

Had that problem when I first bought my Ultra and factory sidecar too. Took it to the dealership and spoke with a real old timer whose been associated with the factory since Christ was a corporal, had road sidecar rigs oftenand he said as long as everything is lined up, the disk wasn't warped,the sqeaking, while annoying, is not a sign of any ongoing damage or malfunction.

I'll keep you posted as I am fixing to take a long ride here shortly.

 

My '03 TLE brake also squeals. Seems like this is common. My solution is to wear ear plugs.

 

You may want to take the pads off the hack, and lightly buff a new surface on them - espacially if the squeal only happens at a certain wheel rpm as you're slowing with brake applied.

Hack