2006 Equinox - ratcheting noise while braking
I recently bought a 2006 Equinox with 113,000 miles on it. The problem I am having is that it makes an unusual ratcheting sound (not real loud, but annoyingly noticeable) when the brake is applied. I've isolated it to the left front wheelwell area. At first I thought it was metal on metal, but the pads are good and rotors look new. It almost sounds like sticking a playing card in and out of the spokes of a bicycle wheel except it sounds plasticky and hollow and rhythmically intermittent, not constant. Or that ratchety sound of a roller coaster going up the track. It makes the sound predominately as I am coming to a stop and slows down as the car slows down (one to one speed related ratio). It'* strongest at say 10 mph to zero. It will even do it if I let the car creep while easing off the brake. It will not make the noise at all with no brake pressure applied. And as for high speed, if it does it all, I can't tell. It doesn't seem to do it in reverse either. I cannot duplicate the problem on jacks; it seems to have to have the weight of the car on it to make the noise. I've looked for things rubbing (i.e. boots, shrouds, etc.) while on jacks and in gear but to no avail. I have not removed the hub or replaced parts yet. I am at a loss to further diagnose this problem and any suggestions would be appreciated. Thanks.