I have 2005 Harley sportser xl 883, Rear brake has a slight squeal noise at very low speed, when brakes are not applied. With rear wheel off the ground, there is a slight drag on the wheel, brake pads look okay, disk is not discolored
My 2007 Ultra developed the same thing while I was vacationing away from home last year. I immediately thought of a bearing, though oddly the noise went away whenever I applied the rear brake. A call to my dealer reassured me that it was nothing more than some dust or sand on the brake pads from parking at the beach. Sure enough, by the time I got home the noise had gone.
Squealing brakes are usually caused by some sort of pad contamination. I had pulsing and slight squealing on my Buell Cyclone brakes. I read online that you should clean the rotor with steel wool or scotchbrite and brake cleaner. Then they said to take the pads out and dress them up on a sheet of medium grit sand paper laid on a flat surface. They had me take the right pad and put it on the left and the left on the right. Oh, you also need to put a very slight bevel on the edges of the pads. It 100% cured the problem and took about 1/2 hour. When it happened again the next season, I replaced the pads with Lyndall Golds and never had a problem again.
The brake pads may look good but could be hardened from not properly releasing. Try flushing the fluid from the rear master cylinder with new fluid but be sure you use the proper fluid. Check your owners manual for the proper type of brake fluid. Dust and dirt buildup can cause the wheel cylinder to malfunction. Remove the wheel cylinder and clean it with brake cleaner. My front brakes on my '02 Roadglide wouldn't release properly. I flushed the fluid and it was fixed. If you still get a squeel then replace the brake pads.
