It's normal to hear the pads making a light noise when you're right by the wheel. Also, since you could press the pistons into the calipers by hand, they are not sticking and very likely glazing is not the issue. Check the caliper mounting bolts to be sure they aren't rusty or bent. The caliper has to be able to slide back and forth sideways freely.
As for the rust I'm referring to, if you look at the hub when the rotor is removed, you will see the wheel studs installed through holes in the hub and there will usually be one or three additional holes between the studs. Water splashes up there, through the holes, and onto the backside of the rotor. That's where the round spots of rust build up. Those have to be scrapped off to insure it will sit perfectly straight on the brake lathe and on the hub. If the rotor is reinstalled in a different orientation with that rust spot still trapped in there, it will prevent the rotor from sitting perfectly parallel to that hub. That will cause the caliper to shake sideways back and forth with each wheel revolution, AND it will make the wheel and tire wobble too.
That said, that isn't the concern here because you installed new rotors so there aren't going to be any rust spots.
The screws you drilled out sound like they are the ones that hold the rotor to the hub. Those are used to hold them on while the car is being flipped around on the assembly line. You don't have to put them back because the wheel will hold the rotor tight.
Getting back to the noise concern, there are many things professionals do to prevent noises and there are some things do-it-yourselfers can do to cause noises. Here's a copy / paste version of a reply I post quite often:
To prevent a crunching sound when cornering, put a light coating of high-temperature brake grease between the hub to rotor contact points. This is especially important on older GM fwd cars. Do not get any grease on the pad or rotor friction surfaces. That includes fingerprint grease. Some very picky shops and mechanics will discard pads that get soiled with any kind of grease, but it is usually sufficient to wash all friction surfaces with brake parts cleaner. If this is done before final assembly, there should be no problem. If that grease is there when the parts get hot from normal braking, the grease will soak into the linings and the porous cast iron rotors. It will cause a squeal and never come out.
Another way to prevent squealing brakes is to remove the sharp edge from the leading surfaces of the linings. I used to use a bench grinder, then switched to a flat file. Now I've found it is sufficient to rub the sharp edges on the concrete floor. That removes the "fingernails on the blackboard" screeching. It seems if you can prevent that squeal during the break-in period, they won't squeal later either.
Run a flat file over the pistons and caliper fingers that contact the outer pads. You don't have to shine those surfaces up. The goal is just to be sure there's no dirt or rust that will prevent flat, even contact between the pads' backing plates and the pistons and calipers. Uneven contact will allow the pads to vibrate more than normal. That can set up an audible squeal. Those same contact points should also be coated with brake grease. That can let the pads vibrate without transferring the noise to the calipers where it will be amplified.
Anyplace the pad backing plates or calipers rest on a metal mounting bracket should also have a light coating of grease. That includes chrome-plated mounting bolts that hold the calipers to the mounts. If those bolts have rust pits or are bent, they should be replaced.
Monday, June 6th, 2011 AT 9:29 PM