Originally Posted by CommuterRun
One thing I have found out is that sometimes temperature will cause brakes to squeal. I had one set of $5 pads that would howl like a banshee when I first started my commute in the morning, but not do it later in the ride, or on the afternoon ride. All the cleaning in the world with different solvents and cleaners didn't help, toe in didn't help, flat pads didn't help, I finally figured out it was the temperature. Anything above the low 50's and they didn't squeal.
I have a similar experience with my bmx bike with chrome plated rims. Anytime my bike goes from the cool basement to the warm outdoors, the brakes squeal like mad from the condensation. That is, if they work!
They squeal when they're clean, too.