I collect and fix bikes for a charity. I have a 26" bike that has the brakes squealing on the front and I can't get rid of it. The wheel is true, I have replaced the pads. The pads are adjusted properly to the wheel and have a slight toe-in. The noise occurs all the way around the wheel. These are v-brakes and the rims are painted aluminum. Any ideas of something else to try would be appreciated.